MEMORANDUM OF DECISION
Pеtitioner is presently incarcerated in the Connecticut Correctional Institution at Somers where he is serving a sentence of seven to ten years pursuant to a judgment of conviction in Fairfield County Superior Court for unlawful sale of heroin (then §§ 8 and 36(a) of Public Acts 1967, No. 555, now Conn.Gen.Stats. §§ 19-452 and 19-480(a), as amended).
I. FACTS
The following facts are not in dispute. At his trial on February 13, 1969, petitioner was identified by Francisco Guzman, an agent of the Bureau of Narcotics and Dangerous Drugs, as the man who sold him two glassine envelopes of heroin on June 7, 1968, while he was parked behind the Midway Diner in Stamford. Guzman, who was not a resident of the area and had never seen petitioner before, based his identification оn two encounters with the seller during a fifteen minute period, one lasting a “couple of moments” and the other *1027 “roughly about a minute more or less.” (Tr., p. 7). During the first encounter, Guzman asked to purchase two bags of heroin. During the second and more critical episode the seller stuck both his hands inside Guzman’s car window, opened his left hand to reveal two glas-sine envelopes containing a quantity of white powder, took the $12 which Guzman offered, and handed Guzman the envelopes. (Tr., pp. 3-4).
The only other witness who testified about the sale was Detective Edward McNulty of the Stamford Police Department, who stated that he was in a car approximately one hundred yards away when the sеller first spoke to Agent Guzman, and that he witnessed the sale from a distance of some forty yards. At that time an automobile was parked between him and Guzman’s car. (Tr., p. 15). When Detective McNulty was then asked whether Guzman was with anyone, he answered, “With an informant.” Defense counsel then asked for the informant’s name, the state’s attorney objected, and the objection was sustained by the trial judge. (Tr., pp. 16-17).
Petitioner presented an alibi defense, introducing testimony and exhibits tending to show that he was in Elizabeth, New Jersey, on the day of the sale.
On appeal, petitioner attempted to argue that the trial judge’s ruling upholding the prosecutor’s objection to disclosure of the informant’s name was erroneous. He relied heavily on Roviaro v. United States,
Petitioner now seeks a writ of habeas corpus in this court, asserting that as a matter of due process of law he was entitled to the name of the informant. Before deciding that question, however, it is necessary to consider whether petitioner has properly exhausted his state court remedies, as required by 28 U.S.C. § 2254(b).
II. EXHAUSTION OF STATE REMEDIES
The Judicial Code, 28 U.S.C. § 2254(b), requires that a state prisoner seeking a federal writ of habeas corpus must first demonstrate that he “has exhausted the remedies available in the courts of the State, or that there is either an absence of available State corrective process or the existence of circumstances rendеring such process ineffective to protect the rights of the prisoner.”
Petitioner’s appeal brief for the Connecticut Supreme Court indicates that he squarely raised the issue of nondisclosure of the informant’s identity: indeed, it was the only issue he raised on appeal. “Since the petitioner raised this issue on direct appeal, no further state court proceedings were necessary for him to exhaust his state remedies,
*1028
and the case is now ready for federal court action.” United States ex rel. West v. LaVallee,
*1029
The fact that the Connecticut Supreme Court refused to consider his argument on the merits does not prevent petitioner from applying to this Cоurt for relief. “The state courts need not have decided the merits of the claims raised by the applicant in the state courts in order for him to be considered to have exhausted his state court remedies. United States ex rel. Meadows v. State of New York,
Accordingly, I hold that petitioner has adequately exhausted his state remedies.
III. THE CONSTITUTIONAL ISSUE
The central question in this case is raised by the Connecticut Supreme Court’s interpretation of Roviaro v. United States,
supra,
in State v. Harris,
supra.
The United States Supreme Court in
Roviaro
held that the “funda
*1030
mental requirements of fairness” dictate the disclosure of an informant’s identity-in certain circumstances,
Beginning with the Supreme Court’s opinion in
Roviaro,
it is evident at the outset that the words which the Court used therein- — -“the fundamental requirements of fairness” — have long connoted a specifically constitutional guarantee. “As applied to a criminal trial, denial of due process is the failure to observe that fundamental fairness essential to the very concept of justice.” Lisenba v. California,
Few courts which have applied the
Roviaro
holding have expressed opinions as to whether the foundation for the requirement of disclosure at trial may be found in the requirements of the Constitution or in the power of the Supreme Court to prescribe evidentiary rules for the lower federal courts. In this circuit, for example, after
Roviaro
was announced, the disclosure requirement was often acknowledged but seldom subjected to close analysis.
6
In United States v. D’Angiolillo,
“The rule emerging from these and earlier decisions is that, where the informer’s testimony may be relevant to the defense, the defendant is entitled to his name, to such information as the government may have concerning his whereabouts, and to reasonable cooperation in securing his appearance.” (fоotnote omitted).340 F.2d at 455 .
It is evident, also, that other federal courts have assumed that the requirement of disclosure in particular circumstances is rooted in the constitutional guarantee of a “fundamentally fair” trial. See Burwell v. Teets,
In addition, the circumstances in
Roviaro
demonstrate that interests of a constitutional magnitude were at issue in that case. In
Roviaro,
two federal narcotics agents and two Chicago police officers worked with an informant described only as “John Doe.” One of the officers, Bryson, hid in the trunk of Doe’s car while Doe drove to a Chicago location to make a purchase of heroin. The others followed in separate cars. After an hour’s wait, Roviaro arrived and immediately sat down in the front seat of Doe’s car beside Doe. They proceeded to a second location, still followed by the law enforcement officers. When Doe’s car stopped at the second location, one of the federal agents, Durham, saw Roviaro alight from the ear, walk to a nearby tree, pick up a small package, return to the ear and make a motion as if depositing the package, thеn wave to Doe and walk away. Durham immedi
*1032
ately went to Doe’s car and seized the package, then signaled Bryson to come out of the trunk. Bryson reported that while secreted in the trunk he had heard Roviaro direct Doe where to drive and when to pull over in order to lose a “tail.” He told Doe that he had brought “three pieces this time.” When Bryson heard Roviaro order Doe to stop, he had lifted the lid of the trunk and observed Roviaro walking to the tree, picking up the package, and returning to the car. He then heard Roviaro say, “Here it is,” and “I’ll call you in a couple of days.” The package contained three glassine envelopes containing a white powder, which chemical analysis revealed contained heroin.
Both in a pre-trial motion and during cross-examination at trial Roviaro’s counsel sought to learn the identity of the informant. His motion was denied and objections to the cross-examination were sustained.
Id.
at 55-56,
Count 2 of the indictment against Roviaro charged that he did “fraudulently and knowingly receive, conceal, buy and facilitate the transportation and concealment after importation of . . . heroin, knowing the same to be imported into the United States contrary to law . . .”
Id.
at 63,
“the Government’s use against petitioner of his conversation with John Doe while riding in Doe’s car particularly emphasizes the unfairness of the nondisclosure in this case. The only person, other than petitioner himself, who could controvert, explain or amplify Bryson’s report of this important conversation was John Doe. Contradiction or amplification might have tended to show an entrapment.” Id.
It is thus manifest that the Court was not concerned merely with the formulation of a rule of evidence: at stake was the basic fairness of the proceedings in which Roviaro had been convicted. 7 And the denial of basic fairness in criminal proceedings is a “violation of the Constitution ... of the United States.” 28 U.S.C. § 2254(a). Lisenba v. California, supra; In re Murchison, supra.
Yet it is equally manifest that the Court was concerned that wholesale requirements of disclosure of informants’ identities would jeopardize effective and necessary law enforcement techniques:
“What is usually referred to as the informer’s privilege is in reality the Government’s privilege to withhold from disclosure the identity of persons who furnish information of violations of law to оfficers charged with *1033 enforcement of that law. The purpose of the privilege is the furtherance and protection of the public interest in effective law enforcement. The privilege recognizes the obligation of citizens to communicate their knowledge of the commission of crimes to law-enforcement officials and, by preserving their anonymity, encourages them to perform that obligation.”353 U.S. at 59 ,77 S.Ct. at 627 .
The Court thus rejected a blanket rule requiring disclosure of an informant’s identity whenever a defendant requested it. Such a rule was not constitutionally required because in many situations nondisclosure of the informant’s identity would in no way affect the “fundamental fairness” of the accused’s trial. 8 Nor was such a rule desirable as an evi-dentiary rule since it would clearly hinder law enforcement officials in their efforts to obtain information from informants. The Court thus recognized that only in certain circumstances may disclosure be required, and proceeded to articulate the primary factors to be considered in determining whether such circumstances are present in any particular case:
“We believe that no fixed rule with respect to disclosure is justifiable. The problem is one that calls for balancing the public interest in protecting the flow of information against the individual’s right to prepare his defense. Whether a proper balance renders nondisclosure erronеous must depend on the particular circumstances of each case, taking into consideration the crime charged, the possible defenses, the possible significance of the informer’s testimony, and other relevant factors.” Id. at 62,77 S.Ct. at 629 .
Considering these factors, the Court held that Roviaro’s constitutional right to a fair trial had been violated.
In light of this analysis there is no contradiction, actual or implied, between the Court's holdings in Roviaro and in McCray v. Illinois, supra. In McCray petitioner asked the court to hold that the identity of an informant must be disclosed at a preliminary hearing to determine whether probable cause existed for an arrest and incidental search of an accused. The Court refused to lay down such а blanket rule, just as it had refused to lay down any such broadsword approach in Roviaro. While fundamental fairness might require disclosure of an informant’s identity at trial under certain circumstances, it clearly did not require such disclosure to all defendants upon request. Nor would the Court blithely strike the “informer’s privilege” from the law of evidence:
“In sum, the Court in the exercise of its power to formulate evidentiary rules for federal criminal cases has consistently declined to hold that an informer’s identity need always be disclosed in a federal criminal trial, let alone in a preliminary hearing to determine probable cause for an arrest or search. Yet we are now asked to hold that the Constitution somehow compels Illinois to abolish the informer’s privilege from its law of evidence, and to require disclosure of the informer’s identity in every such preliminary hearing where it appears that the officers made the arrest or search in reliance upon facts supplied by an informer they had reason to trust.” (emphasis added).386 U.S. at 312 ,87 S.Ct. at 1063 .
In McCray, the Court was even less impelled by considerations of “fundamental fairness” to impose an absolute rule of disclosure than in Roviaro because ultimate questions of guilt or innocence are not at issue in the preliminary proceeding. And if an evidentiary rule of disclosure would not be imposed at trial, it certainly would not be imposed at a preliminary hearing:
“What Roviaro thus makes clear is that this Court was unwilling to impose any absolute rule requiring dis *1034 closure of an informer’s identity even in formulating evidentiary rules for federal criminal trials. Much less has the Court ever approached the formulation of a federal evidentiary rule of compulsory disclosure where the issue is the preliminary one of probable cause, and guilt or innocence is not at stake.” (emphasis added).386 U.S. at 311 ,87 S.Ct. at 1062 .
This is not the first time the Court has distinguished between procedures bearing upon the determination of guilt and those dealing with other phases of the criminal process. See Williams v. New York,
Thus as the law comes down to us now, disclosure of an informant’s identity is not required at a preliminary hearing to determine probable cause, 9 and it is mandatory at trial only when the crime charged, the possible defenses, and the possible significance of the informer’s testimony are such that the “fundamental requirements of fairness” so require. Roviaro v. United States, supra. Of course this analysis in no way enlarges upon the doctrine articulated in Roviaro, but only reaffirms the Court’s determination to protect the right of the accused to basic fairness in the determination of his guilt or innocence. We need not indulge in semantic gymnastics or turn conceptual somersaults over the fact that the Supreme Court did not specifically denote the Due Process Clause as the basis for its decision in Roviaro: it is beyond peradventure that the right to a trial in which the “fundamental requirements of fairness” are secured is a right essential to, and at the very heart of, the protections guaranteed by our Constitution. Even where what was at stake was only the degree of punishment rather than the fundaméntal issue of guilt or innocence, the Supreme Court held that suppression by the prosecution of evidence favorable to the accused upon request violates constitutional guarantees where the evidence is material either to guilt or to punishment, irrespective of the good faith or bad faith of the prosecution:
“The principle of Mooney v. Holohan [294 U.S. 103 ,55 S.Ct. 340 ,79 L.Ed. 791 (1935)] is not punishment of society for misdeeds of a prosecutor but avoidance of an unfair trial to the accused. Society wins not only when the guilty are convicted but when criminal trials are fair-, our system of the administration of justice suffers when any accused is treated unfairly. An inscription on thе walls of the Department of Justice states the proposition candidly for the federal domain: ‘The United States wins its point whenever justice is done its citizens in the courts.’ A prosecution that withholds evidence on demand of an accused which, if made available, would tend to exculpate him or reduce the penalty helps shape a trial that bears heavily on the defendant. That casts the prosecutor in the role of an architect of a proceeding that does not comport with standards of justice, even though, as in the present case, his action is not ‘the result of guile,’ to use the words of the Court of Appeals.226 Md., 422 , at 427,174 A.2d 167 .”
Brady v. Maryland,
Having concluded that the disclosure of an informant’s identity may be constitutionally required in certain circumstances, it is now necessary to determine whether petitioner’s case presents such circumstances.
Neither
Roviaro
nor the leading case in this circuit, United States v. D’Angiolillo,
supra,
offer specific touchstones for determining when disclosure of the informant’s identity is “relevant and helpful to the defense of the accused.” A definite rule of thumb, however, has developed: where the informant was a witness or a participant in the allеged crime, disclosure of his identity is required. On the other hand, where the informant was not a participant or witness,
e.g.
where he merely introduced undercover law enforcement officers to a suspected drug dealer but was not involved in any later transactions between the parties, disclosure is not required.
10
Such is the rule in this circuit, United States v. Roberts,
“In striking this balance as we do today, we find ourselves in accord with every other federal appellate court, including a panel of this Court in Anderson v. United States,106 U.S.App.D.C. 340 ,273 F.2d 75 , cert. denied,361 U.S. 844 ,80 S.Ct. 95 ,4 L.Ed.2d 81 (1959), which has had occasion to consider the disclosure problem since Roviaro. The lower federal courts have consistently held that Roviaro does not require disclosure of an informant who was not an actual participant in or a witness to the offense charged. See, e.g., Rocha v. United States,401 F.2d 529 (5th Cir. 1968), cert. denied,393 U.S. 1103 ,89 S.Ct. 905 ,21 L.Ed.2d 796 (1969); Jimenez v. United States,397 F.2d 271 (5th Cir. 1968); Churder v. United States,387 F.2d 825 , 831-832 (8th Cir. 1968); Lannom v. United States, supra,381 F.2d 858 , 861-862 (9 Cir.); Rodriguez-Gonzalez v. United States,378 F.2d 256 , 258-259 (9th Cir. 1967); Garcia v. United States,373 F.2d 806 , 808 (10th Cir. 1967); United States v. Pitt,382 F.2d 322 , 325 (4th Cir. 1967); Zaroogian v. United States,367 F.2d 959 , 962 (1st Cir. 1966); United States v. Russ, supra,362 F.2d 843 , at 844-846 (2 Cir.); Garibay-Garcia v. United States,362 F.2d 509 , 510 (9th Cir. 1966); Cook v. United States,354 F.2d 529 , 531 (9th Cir. 1965); Marderosian v. United States,337 F.2d 759 , 760-761 (1st Cir.), cert. denied,380 U.S. 971 ,85 S. Ct. 1328 ,14 L.Ed.2d 268 (1964); United States v. Konigsberg,336 F.2d 844 , 848 (3d Cir.), cert. denied,379 U.S. 933 ,85 S.Ct. 334 ,13 L.Ed.2d 344 (1964); Bruner v. United States,293 F.2d 621 (5th Cir.), cert. denied,368 U.S. 947 ,82 S.Ct. 388 ,7 L.Ed.2d 343 (1961); Miller v. United States,273 F.2d 279 , supra at 280-281 (5 Cir.); Pegram v. United States,267 F.2d 781 (6th Cir. 1959). Conversely, disclosure has been required where the informant was an active participant or was present at the scene of the crime. See, e.g., Lopez-Hernandez v. United States,394 F.2d 820 (9th Cir. 1968); United States v. Roberts,388 F.2d 646 , 648-649 (2d Cir. 1968) ; Gilmore v. United States,256 F.2d 565 , 566- *1036 567 (5th Cir. 1958).” (emphasis added).
See, also, United States v. Lloyd,
At petitioner’s trial, Detective McNulty testified that the informant was with Agent Guzman during the transaction for which petitioner was indicted. While possibly not an active participant, the informant was certainly a witness close at hand throughout the entire transaction. This would be sufficient to bring petitioner within
Roviaro, D’Angiolillo,
and
Roberts, supra,
which collectively establish that it is reversible error for a trial judge to allow a government witness to refuse tо disclose an informant’s name when the informant is a witness to the alleged crime and the informant’s name is requested by the defendant at his trial.
Cf.
United States v. Smart,
Moreover, the consideration of “the possible defenses” and “the possible significance of the informer’s testimony” which
Roviaro
requires demonstrates the unfairness of which petitioner complains. As in
Roviaro,
unless petitioner waived his constitutional right not to take the stand in his own defense, the informant was his sole material witness, the only eyewitness to the crime who was not a law enforcement officer. In addition, petitioner maintained that he was in New Jersey on the day of the alleged crime and presented evidence tending to support his alibi. Identification of the man who dropped the packages into Agent Guzman’s car on June 7, 1968, was thus a crucial aspect of the proceedings at petitioner’s trial, and the informant’s testimony would have been “highly relevant” to such identification and “might have been helpful” to petitioner’s defense. Roviaro v. United States,
supra,
IT IS ORDERED that a writ of ha-beas corpus should issue out of this court discharging the petitioner from custody, unless petitioner, Perry Hawkins, is afforded a new trial within sixty days at which the government shall disclose the name of the informant and such information as it has concerning his current whereabouts, and at which the government shall provide reasonable cooperation in securing the appearance of the informant.
Notes
. Section 226 of the Connecticut Practice Book provides:
“Whenever an objection to the admission of evidence is made, counsel shall state the grounds upon which it is claimed or upon which objection is made, succinctly and in such form as he desires it to go upon the record, before any discussion or argument is had. Argument upon such objection shall not be made by either party unless the court requests it and, if made, must be brief and to the point. An exception to the ruling must be taken in order to make it a ground of appeal.”
. Petitioner was not required, as a matter of federal law, to seek state habeas corpus before applying to this Court for a federal writ. “Under the traditional concepts of exhaustion only one opportunity through proper channels need be afforded a state to pass upon a question before the habeas court should look to the merits.” United States ex rel. Weinstein v. Fay,
“Section 2254 does not erect insuperable or successive barriers to the invocation of federal habeas corpus. The exhaustion requirement is merely an accommodation of our fеderal system designed to give the State an initial ‘opportunity to pass upon and correct’ alleged violations of its prisoners’ federal rights. Fay v. Noia,
Moreover, it is evident that the courts of the state of Connecticut are now effectively closed to petitioner’s claims. As a general rule, the rejection by the Connecticut Supreme Court of petitioner’s claim рrevents him from raising it anew in a state habeas proceeding because of Connecticut’s rule that habeas corpus cannot serve as an appeal for questions which might have been raised for direct review. Wojculewicz v. Cummings,
“We hold, therefore, that a petitioner may collaterally raise federal constitutional claims in a habeas corpus proceeding even though he has failed to appeal his federal constitutional claims directly to us if he alleges and proves, by a fair preponderance of the evidence, facts whiсh will establish that he did not deliberately bypass the orderly procedure of a direct appeal.” Vena v. Warden,154 Conn. 363 , 366-367,225 A.2d 802 , 804 (1966).
The
Vena
doctrine is of no avail to petitioner, however, because in State v. Harris,
Additionally, the Connecticut Supreme Court expressly rejected petitioner’s claim on direct appeal because his trial counsel had failed to comply with procedural requirements during trial:
“Neither the grounds on which the objection was based nor the grounds on which the question was claimed were stated by counsel as required by Practice Book § 226
“In addition, the record shows no exception was taken to this ruling on evidence so as to make it a ground of appeal.”
Yet it is evident that petitioner’s trial counsel had the issue of identification uppermost in his mind during his cross-examination of Agent Guzman and Detective McNulty and that he brought this issue clearly before the trial judge. He questioned Guzman as to the brief period of time in which he had an opportunity to observe the seller (Tr., p. 7) and sought to raise the possibility of confusion in the identification with other persons from whom Guzman had bought drugs on June 7 and during the month. (Tr., p. 8). He questioned McNulty as to the distance from which he had observed the seller and the vehicle obstructing his view of Guzman’s car. (Tr., pp. 15-16). Following objection to one of his questions, he expressly stated that he was raising the issue of identification (Tr., p. 8). It was in this context that he sought the name of the informant (Tr.,
*1029
p. 17). While the trial counsel might well have been more aggressive in seeking the name of the informer and specifying the reasons therefor, the request was specific and the possible value to petitioner of the informant’s testimony sufficiently apparent for the trial judgе to be apprised of the significance of the request. When petitioner claims error for denial of disclosure of the identity of the only eyewitness to the crime who was not a law enforcement officer, there is no “trial by ambuscade of the judge.” State v. Hawkins,
supra,
. The failure of petitioner’s trial counsel tо comply with the requirements of § 226 of the Practice Book does not bar this Court from granting petitioner relief. “Questions of due process are not to be treated ‘narrowly or pedantically, in slavery to forms or phrases.’ ” Pearson v. McGraw,
“If this rejection by the state court of the opportunity to pass upоn this element of the petitioner’s claim because of insistence upon compliance with its procedural rules forecloses him from having it passed upon in Connecticut courts in a post-conviction proceeding, as it probably does because of Connecticut’s rule that habeas corpus cannot serve as an appeal for questions which might have been raised for direct review, Wojculewicz v. Cummings,143 Conn. 624 , 628,124 A.2d 886 (1956) ; In re Bion,59 Conn. 372 , 386,20 A. 662 (1890) ; Brisson v. Warden,25 Conn.Sup. 202 , 205,200 A.2d 250 (1964), this court may, nonetheless, consider it in this habeas corpus proceeding, cf. Henry v. Mississippi,379 U.S. 443 ,85 S.Ct. 564 ,13 L.Ed.2d 408 (1965) ; unless, of course, petitioner’s failure to comply constituted a deliberate bypassing of orderly state procedure within the meaning of Fay v. Noia,372 U.S. 391 ,83 S.Ct. 822 ,9 L.Ed.2d 837 (1963). Surely, thеre was no deliberate by-passing here, for an attempt was made to have the state Supreme Court pass on this particular facet of his constitutional claim under the same evidence already contained in the record. Such a situation is far outside the qualification of Fay v. Noia.”
. The issue of whether disclosure of an informant’s identity is solely a matter of evi-dentiary rules, or may in certain circumstances be constitutionally required, is also central to the determination of whether this Court properly has jurisdiction over petitioner’s claim. The Judicial Code, 28 U.S.C. § 2241 (c) provides:
“The writ of habeas corpus shall not extend to a prisoner unless—
(3) he is in custody in violation of the Constitution or laws or treaties of the United States. ...”
28 U.S.C. § 2254(a) provides:
“The Supreme Court, a Justice thereof, a circuit judge, or a district court shall entertain an application for a writ of habeas corpus in behalf of a person in custody pursuant to the judgment of a State court only on the ground that he is in custody in violation of the Constitution or Inm or treaties of the United States." (emphasis added).
Inasmuch as the question of jurisdiction and petitioner’s claim on the merits are intimately bound together, they will be considered conjointly in the following discussion.
. “The aim of the requirement of due process is not to exclude presumptively false evidence, but to prevent fundamental unfairness in the use of evidence, whether true or false.” Lisenba v. California,
supra,
.
See, e. g.,
United States v. White,
. Where the very integrity of the fact-finding process is at issue,
i. e.,
in the presentation or exclusion of evidence directly relating to the accused’s innocence or guilt at trial, the Supreme Court has determined the accused’s “fundamental” rights to be of constitutional origin.
See
Mapp v. Ohio,
. See, e. g., Rugendorf v. United States,
. This is the teaching of McCray, as noted by our. Court of Appeals:
“There is no absolute сonstitutional right to disclosure of the identity of an informer at every hearing on a motion to suppress. See, e. g., McCray v. Illinois,386 U.S. 300 ,87 S.Ct. 1056 ,18 L.Ed.2d 62 (1967) [footnote omitted].”
United States v. Tucker,
Moreover, it is significant that in
McCray
the Court was sharply divided, but the four dissenters felt no need to discuss whether the disclosure requirement -
at trial
was constitutionally based: rather, they argued the much broader position that disclosure of the informant’s identity is constitutionally required
at a hearing to determine whether probable cause existed for an arrest or search.
. Thus in Rugendorf v. United States,
supra,
the Supreme Court held that disclosure was not required where there was “not even an intimation” that the informant “had played a direct and prominent part, as the sole participant with the accused, in the very offense for which the latter was convicted.”
Id.