Carl Montgomery petitioned the district court for a writ of habeas corpus pursuant to 28 U.S.C. § 2254. He challenged the constitutionality of his state conviction for residential burglary on the ground that he was denied the effective assistance of counsel guaranteed by the sixth amendment. The Honorable Richard Mills of the Central District of Illinois reviewed the petition and granted the writ. The state appeals. We agree with Judge Mills that the petitioner was denied effective assistance of counsel and therefore affirm.
I
BACKGROUND
A. Facts
The petitioner was arrested and charged with the commission of two separate burglaries occurring on the same day, one in Moultrie County, Illinois and the other in Macon County, Illinois. He was tried in Moultrie County in March 1984. The jury found him guilty, and he received a seven-year prison sentence. In April 1984, following the Moultrie County conviction, the petitioner was tried in Macon County for the second offense. The Macon County jury acquitted the petitioner. The only difference between the evidence presented in the two trials was the testimony — presented in the Macon County trial but not in the Moultrie County trial — of a disinterested witness who placed the petitioner in Springfield on the day of the burglaries. The following is a brief synopsis of the testimony at both trials taken from the state appellate court opinion in Mr. Montgomery’s post-conviction petition for a new trial: 1
Testimony at the Moultrie County trial held on March of 1984 was elicited as follows: The State's first and primary witness, defendant’s half-brother Wayne (Butch) Montgomery, testified that the defendant drove down from Springfield and met him at his father’s cabin in Beardstown at about 8:30 or 9:00 the morning of September 9, 1983. The two men discussed a possible burglary in Ar-eola. Wayne’s wife, Mary Lou, was present during part of that discussion. She later testified that she overheard their burglary plans, and that she observed the two men drive away in defendant’s car. Wayne stated that he and the defendant later drove around, but abandoned their Areola burglary plans because too many people were present in the area. Instead, they eventually burglarized a home in Moultrie County and a home in Macon County. They then drove back to defendant’s residence in Spring *409 field, arriving there about 8:30 or 9:00 that evening. At this point, defendant made several telephone calls to two people, John Mardis and Orville Bartells, whom he and his half-brother though [sic] might be able to “move” the merchandise. According to Wayne Montgomery, he and defendant drove to the home of Orville Bartells in Chandlerville, leaving around 10:00 p.m.
Wayne also testified that he pleaded guilty to this burglary as well as others, but he did not expect to gain any favoritism based on his testimony in the present case. On cross-examination, Wayne admitted that he had prior convictions for burglary and battery.
Defendant’s brother Dale Montgomery and his girlfriend Betty Simons both testified that they were at defendant’s Springfield residence the evening of September 9, 1983, when they observed defendant and Wayne arrive at the house together. Dale and Betty stated they left defendant’s home at about 9:00 p.m.
An exhibit was admitted into evidence containing a record of telephone calls made from the defendant’s home the night of September 9. The itemized phone bill listed long-distance calls made to Mardis’ home at 9:33 and 9:50 p.m., and a phone call to Bartells’ residence at 9:43 p.m. The phone bill also showed numerous other calls made to these two people over a period of time; defendant stated they were his friends.
Defendant’s wife, Carol Montgomery, testified for the defense. She stated that the events of September 9, 1983, stuck out in her mind because it was their son’s birthday. She stated that she and defendant went to the Sears store in Springfield that afternoon to purchase a bicycle as a present for their son. She also testified that defendant was around the house most of the day working on a car. She further stated that a group of family and friends came to the house that evening for a birthday party. She denied that Dale Montgomery and Betty Simons had stopped by the evening of September 9, recalling that they came over the next night instead.
In all, some 12 witnesses testified on behalf of the defendant that they had observed him in and around Springfield September 9. Many also testified that they were present for the birthday party in the evening, but that Wayne Montgomery, Betty Simons, and Dale Montgomery were never at the defendant’s home. Significantly, all of these witnesses were either relatives or close friends of the defendant’s family.
At the conclusion of all the evidence, the jury found the defendant guilty of residential burglary. This court affirmed his conviction on appeal.
During the Macon County trial in April of 1984, Barry Holtkamp, a Sears employee in the Springfield store, was called to testify. He stated that defendant and his wife had purchased a bicycle from him at about 1:15 or 1:30 the afternoon of September 9, 1983. Holtkamp testified that he remembered the defendant because it was the only bicycle sale he made that day. Holtkamp further recalled that defendant had joked about the bike being “junk,” but because it was cheap, he would buy it anyway.
People v. Montgomery,
B. Procedural History
After the Appellate Court of Illinois affirmed his Moultrie County conviction on direct appeal,
People v. Montgomery,
defendant and his wife had given him a receipt for the Sears purchase on September 9 and requested he investigate *410 this potential witness, but that he failed to do so. Kesinger stated this was merely due to “inadvertence” on his part, as he was busy interviewing other potential witnesses. Kesinger further stated:
“I was given just a receipt. I wasn’t given a name so I didn’t know who to interview until I found out who the witness was. But at that point, I simply didn’t believe the defendant so I didn’t think it happened.”
Kesinger noted that the sales receipt had an employee code number on it, which defendant’s wife and mother-in-law, on their own initiative, used to locate the witness.
Montgomery,
Mr. Montgomery then appealed. The Appellate Court of Illinois held that the totality of the circumstances did not support a finding of attorney incompetence and affirmed the state trial court’s denial of the petition.
Id.
II
DISTRICT COURT OPINION
Judge Mills began his analysis of the ineffective assistance issue with an explication of
Strickland v. Washington,
Applying this analysis to the facts, Judge Mills found, initially, that Mr. Kesinger’s failure to investigate the Sears receipt was a serious error in professional judgment and “was not related in any way to trial tactics or strategy.”
Montgomery v. Pet
*411
ersen,
Judge Mills then found that the petitioner also had met his burden of showing that a reasonable probability existed that “but for counsel’s unprofessional errors, the result of the proceeding would have been different.”
Strickland,
Not only would the unbiased alibi witness’ testimony greatly enhance the defense case if it stood alone, it also lends even greater support to defendant’s case when we consider the fact that it corroborates the otherwise impeachable testimony of 12 additional alibi witnesses. It is unrealistic to look at this testimony as simply cumulative.
Montgomery,
Further, and in what is indeed a rare occurrence, we have evidence of a trial based on almost identical facts as a basis for comparison. In the second trial, the disinterested alibi witness was called and Petitioner was acquitted. This is strong evidence that the result would have been different but for counsel’s errors. We agree with the Illinois Appellate Court that all trials are sui generis and that the results of the Macon County trial do not necessarily compel the conclusion that Petitioner would have been acquitted if Holtktramp [sic] was called in the Moultrie County trial. It is certainly true that other factors do play a part in the results of trials.
However, Petitioner’s burden is not that overwhelming. Strickland specifically disavowed use of an outcome determinative test in making out a finding of prejudice. Strickland,466 U.S. at 693, 694 ,104 S.Ct. at 2068 . Petitioner must only show a reasonable probability of a different outcome. For us, the results in the Macon County trial go a long way in showing that probability. Furthermore, this is not a case where the other evidence brought by the state would overwhelmingly favor a finding of guilty. Hence, when the evidence is looked at in its totality, we believe the error of counsel “undermine[d] confidence in the outcome” and thus deprived defendant of his fundamental right to a fair trial in violation of the Sixth Amendment.
Id.
Ill
DISCUSSION
This case requires that we apply principles of law that have been settled since the Supreme Court’s holding in
Strickland v. Washington,
A. Performance of Counsel
As we noted in Sullivan:
With respect to the “performance” component, “the proper standard for attorney performance is that of reasonably effective assistance.”
Strickland,
No particular set of detailed rules for counsel’s conduct can satisfactorily account for the variety of circumstances faced by defense counsel or the range of legitimate decisions regarding how best to represent a criminal defendant. Any such set of rules would interfere with the constitutionally protected independence of counsel and restrict the wide latitude counsel must have in making tactical decisions. Id. at 688-89,104 S.Ct. at 2065 .
Sullivan,
This case, like
Strickland,
involves an ineffective assistance claim based on counsel’s failure to investigate. In this type of case, the temptation to rely on hindsight is particularly strong and, consequently, we must take special pains to guard against the inadvertent use of such a methodology. Rather, we must follow the specific direction of the Supreme Court that “strategic choices made after thorough investigation of law and facts relevant to plausible options are virtually unchallengeable....”
Id.
at 690,
In our view, the district court was correct in its determination that, under the facts of this case, counsel did not make a reasonable decision that further investigation was unnecessary. At the outset, it is important to keep in mind that trial counsel’s failure to investigate the Sears receipt was
not,
by counsel’s own admission, a strategic decision. Rather, he testified that his failure was due to “inadvertence” as well as the fact that he “simply didn’t believe” the petitioner. In
Strickland,
the Supreme Court noted that information supplied by the defendant is a prime source of the factual bedrock upon which counsel must rely in making strategic choices.
Id.
at 691,
Cosey’s entire defense at trial rested on discrediting the state’s main witness— the victim. The five proffered witnesses would not only have corroborated Co-sey’s story and further impeached the victim’s version, but, as the state conceded in oral argument, if the witnesses were believed, their testimony alone *413 would have entirely exculpated Cosey. Without interviewing and investigating such promising witnesses, Cosey’s attorney had no reason to believe they would not be valuable in securing Co-sey’s release. Although three of the witnesses had an apparent reason to be biased in Cosey’s favor, that alone is insufficient cause to automatically reject them. Moreover, two of the proffered witnesses had no apparent reason for bias. There was no strategy involved here, only negligence.
Id.
at 658 n. 3 (emphasis supplied);
3
see also United States v. Debango,
It is, of course, not necessary that defense counsel “track down every lead” or “personally investigate every evidentiary possibility before choosing a defense and developing it.”
Sullivan,
Unlike many of the “failure to investigate” cases that have come before this court and the other circuits, this is not a case where counsel totally failed to present a defense. However, the importance of the information that was not tracked down and presented to the jury is, under the facts of this case, extraordinarily significant. Here, the Sears clerk can hardly be characterized as a cumulative alibi witness. Rather, he was the
only
disinterested witness in the case. All twelve of the other defense witnesses were either close friends or relatives of the petitioner. The testimony presented to the Moultrie County jury basically “boiled down to a swearing match between a prosecution witness, who admitted committing the crime, and [the petitioner], who denied any part in it.”
Nealy v. Cabana,
The other additional witnesses who testified at trial did not alter the basic nature of this case as a “swearing match” between the accomplice and the petitioner. Wayne Montgomery’s testimony was corroborated by the testimony of his wife Mary Lou, Dale Montgomery, and Betty Simons. The petitioner’s alibi defense was corroborated by twelve witnesses, all family members or friends, who directly contradicted Wayne Montgomery. The jury was presented with a straightforward credibility choice. Every one of these witnesses had a reason to be biased. Given the standoff between two factions in this family, one group supporting Wayne Montgomery and the other group supporting the petitioner, independent corroboration by a neutral, disinterested witness would perforce be extremely significant.
See People v. McVay,
We believe that the district judge, who was able to draw on his long experience as a state trial judge, correctly concluded that defense counsel, even without the benefit of hindsight, should have recognized the crucial importance of the Sears clerk as a witness. We recognize that defense counsel was not given the witness' name-just the initialed sales receipt. However, the petitioner explained to Mr. Kesinger what the receipt was for and why it might be important to his defense. The fact that Mr. Kesinger did not have the name or address of the sales clerk did not present a significant obstacle to locating him, as evidenced by the ease with which the petitioner's wife and mother-in-law were able to find him. Thus, this is not a case where counsel's failure to locate a particular witness may be excused. See United States ex rel. Kleba v. McGinnis,
B. Prejudice of Counsel’s Errors
We now turn to the prejudice prong of the
Strickland
test. “An error by counsel, even if professionally unreasonable, does not warrant setting aside the judgment of a criminal proceeding if the error had no effect on the judgment.”
Strickland,
The focus of the inquiry must be on what information would have been obtained from such an investigation and whether such information, assuming its admissibility in court, would have produced a different result. Under usual circumstances, we would expect that such information would be presented to the habeas court through the testimony of the potential witnesses. “Complaints of uncalled witnesses are not favored in federal ha-beas review.” Murray v. Maggio,736 F.2d 279 , 282 (5th Cir.1984).
Id. at 1016.
In this case, unlike so many cases involving a similar claim of failure to call potential witnesses,
5
the petitioner has pointed to a specific witness whose missing testimony would have been exculpatory. In fact, the Sears witness’ testimony was significant to the petitioner’s defense in several respects. First, it directly contradicted the state’s chief witness, who testified that he and the petitioner were together outside of Springfield from 9:00 a.m. until 9:00 p.m. that day.
See Nealy,
Furthermore, this is not a case where the evidence of the petitioner’s guilt is overwhelming. Rather, the state’s case depended on the relative credibility of Wayne Montgomery and the petitioner. Because the verdict against the petitioner rested primarily on the testimony of the confessed accomplice, it is “ ‘more likely to have been affected by errors than one with overwhelming record support.’”
Nealy,
Finally, the petitioner’s acquittal in the Macon County trial is persuasive evidence
*416
that the omission of defense counsel in this case was prejudicial. We agree with Judge Mills that the Illinois appellate court’s comment that every trial is
sui generis
may be accurate but misconceives the petitioner’s burden of proof under
Strickland.
In order to demonstrate prejudice, the petitioner need only establish a
reasonable probability
that the Sears witness’ testimony would have changed the jury’s verdict.
Strickland,
All of the factors discussed above, independently and in combination, undermine our confidence in the outcome of the Moul-trie County trial. Therefore, we conclude that the petitioner has met his burden in showing that his defense counsel’s failure to secure the testimony of the Sears witness was prejudicial.
Accordingly, the judgment of the district court is affirmed.
Affirmed.
Notes
. In granting the petition for writ of habeas corpus, Judge Mills relied upon the summary of facts contained in the state appellate court opinion. He did not review the transcript of the underlying state trial and did not hold a new evidentiary hearing.
Montgomery v. Petersen,
. We note that, in the district court and in this court, Mr. Montgomery has been represented by other counsel. R. 1 & 4 at 4.
. The court went on to find that counsel’s inadequate performance had prejudiced the defendant.
United States ex rel. Cosey v. Wolff,
. Although the testimony of an accomplice is a sufficient basis upon which the jury may convict,
People v. Wilson,
.
See, e.g., Dees v. United States,
. Although it is not entirely clear what the state’s argument is, the state appears to question in its brief Judge Mills’ classification of the Sears witness as an "alibi” witness. Appellant’s Br. at 8 n. 1. We think such an argument is particularly unconvincing in light of the fact that the state never contended at the Macon County trial, or at oral argument in this appeal, that the petitioner could have purchased the bicycle at the Sears store in Springfield and still have committed the burglaries with Wayne Montgomery. "A defense that places the defendant at the relevant time in a different place than the scene involved and so removed therefrom as to render it impossible for him to be the guilty party” is an alibi defense. Black’s Law Dictionary 66 (5th ed. 1979). Under Wayne Montgomerys version of the crime, the petitioner spent the entire day with him outside of Springfield planning and executing the burglaries. Thus, the testimony of the Sears witness, if believed, rendered it impossible for the petitioner to be the guilty party under the prosecution’s theory of the case, as presented through the testimony of the professed accomplice.
