OPINION OF THE COURT
In this consolidated appeal, we are asked to review the sentences of Samuel Roman, who pled guilty to possession with intent to distribute cocaine base and aiding and abetting, and Oscar Roman, who pled guilty to possession with intent to distribute and distribution of cocaine base as well as carrying a firearm in connection with a drug trafficking crime. The district court sentenced both Samuel and Oscar Roman to 188 months of imprisonment for the drug related offenses and imposed a consecutive sentence of five years on Oscar Roman for the firearm offense. Both defendants contend that the district court erred by imposing enhancements for “crack cocaine” and concluding that the government had not breached their plea agreements by refusing to file a downward departure motion. Samuel Roman raises the additional argument that the district court erred by refusing his request for funds to retain a psychologist to testify on his behalf at sentencing. For the reasons that follow, we will affirm.
I.
These prosecutions are based on three separate incidents. On September 2, 1994, during surveillance of the 4400 block of North 4th Street, Philadelphia police officers observed Bobby Rodriguez and an unknown purchaser engage in a drug transaction with Samuel Roman. After the purchaser paid Rodriguez for the drugs, he handed the money to Roman. The police stopped Rodriguez and Roman and seized fifty vials of crack cocaine from Rodriguez and $494 in cash from Roman.
On November 7, 1994, Philadelphia police officers, again surveilling the 4400 block of North 4th Street, saw William Serrano engage in a drug sale. An undercover officer *139 then approached and purchased two vials of crack from Serrano. Serrano then handed the money to Oscar Roman, who was seated in a nearby car. Backup officers arrested Serrano and Roman. They seized eleven vials of crack from Serrano and a loaded weapon and $259 in cash from Roman. A subsequent search of the ear disclosed additional “bundles” containing numerous vials of crack cocaine.
On November 22,1994, police officers were once again surveilling the same block of North 4th Street when they saw Samuel Roman hand a brown paper bag to Oscar Roman and another individual. Oscar Roman and the other individual then hid the paper bag in a vacant lot. Samuel collected money from the two and left. Police apprehended Samuel in a car shortly thereafter. They found $1,494 on his person and a bundle of suspected crack cocaine in the car. The officers searched the vacant lot and found the brown paper bag that Oscar and the other individual had hidden. It contained fourteen bundles of crack, and three more bundles were found nearby.
Samuel and Oscar Roman both were charged with possession with intent to distribute crack cocaine (21 U.S.C. § 841(a)(1)), and Oscar Roman was also charged with distribution of crack cocaine (21 U.S.C. § 841(a)(1)) and carrying a firearm in connection with a drug-trafficking crime (18 U.S.C. § 924(e)). Defendants were initially named in an indictment that specifically charged them with offenses involving “crack cocaine.” However, the government obtained a superseding indictment that identified the controlled substance at issue as “cocaine base.”
Both defendants pled guilty to all of the offenses in the superseding indictment pursuant to standard written plea agreements. In those agreements, each defendant agreed “to provide truthful, complete, and accurate information,” “to provide all information concerning his knowledge of, and participation in, the distribution of cocaine base and any other crimes about which he has knowledge,” and not to “protect any person or entity through false information or omission.” App. at 19a-20a, 26a-27a. During the change-of plea hearings that followed their initial plea of not guilty, the government clarified their obligations under the plea agreements by acknowledging that defendants could provide historical information only, and did not have to “engage in affirmative investigative techniques.” App. at 59a.
A sentencing hearing was held on October 16, 1996. Both defendants argued that the government had the burden of proving that the controlled substance involved in this case was crack cocaine. To meet its burden, the government only presented the testimony of Officer Wilbert Kane, the officer assigned to the case. Kane had twelve years of experience in investigations and prosecutions of persons charged with crack cocaine distribution and had trained state and federal narcotics officers. Over defense objections, Kane testified that the substance seized from defendants was crack cocaine. His conclusion was based solely upon the way the substance was packaged. Kane conceded that the substance seized from the defendants did not contain sodium bicarbonate, a residue common in crack cocaine. However, he explained that the head of the police laboratory had told him that the absence of sodium bicarbonate did not mean the substance was not crack because, if the “cook” was good, sodium bicarbonate would not be found in the finished crack. App. at 74a.
Kane testified that he had seen crack cocaine cooked and that he had seen the substance that was seized from the defendants. For some reason, he was not asked to compare that crack’s appearance with the substance seized from the defendants. He did, however, testify that the drugs taken from the defendants was in vials with color caps which is how crack cocaine is typically packaged for sale in Philadelphia. He testified that “powder cocaine,” in contrast, is usually packaged in ziploek bags. App. at 75a. Based solely upon the packaging, Kane concluded that the substance seized from the defendants was crack. The court accepted that conclusion and sentenced the defendants accordingly over defense objections.
Defendants also objected to the government’s decision not to file a downward departure motion. They argued that this decision *140 breached their plea agreements and that government investigators were angry because they were only able to provide “historical” information. The defendants maintained that they only had historical information and that their agreements did not require them to provide more. The government, however, argued that it was the Romans who breached the agreement by not providing complete information. In support of its argument, the government again presented the testimony of Officer Kane who testified that “the accumulation of intelligence that [the Romans] would have gathered while in the business far exceeded what they were willing to tell us in the proffer.” App. at 83a. Kane conceded, however, that the information the Romans had provided was accurate. The district court concluded that the government had not breached the plea agreements.
Samuel Roman was sentenced at the bottom of the applicable guidelines range to 188 months imprisonment. Oscar Roman was also sentenced to 188 months on the narcotics offenses as well as to a consecutive sentence of 60 months stemming from his 924(c) conviction. These appeals followed.
This Court has jurisdiction to review final sentences pursuant to 18 U.S.C. § 3742(a).
Discussion
II.
Defendants contend that the district court erred in finding that the controlled substance involved in their case was crack cocaine and sentencing them pursuant to the guideline enhancement for that drug.
1
The district court’s determination that the substance seized from defendants was crack cocaine is a finding of fact that we review for clear error.
See United States v. Johnson,
In support of their argument, defendants cite our recent decision in United States v. James. There, the defendant was charged with distribution and possession of a “substance containing a detectable amount of cocaine base.” Id. (emphasis added). He plead guilty to that charge and stipulated for sentencing purposes that “the relevant quantity of cocaine base is 57.4 grams.” Id. at 856 (emphasis added). At his plea colloquy the court asked “Now Mr. James, did you, as charged in Count One of the indictment ... knowingly, intentionally and unlawfully distribute in excess of five grams of a mixture and substance containing a detectable amount of cocaine base?” Id. (emphasis added). James answered this question affirmatively. However, during the plea colloquy, the government made several casual references to “crack”:
The parties agree that the relevant quantity of cocaine base ... is 57.4 grams., That’s the total net weight of the crack cocaine that was purchased....
Mr. James exchanged a plastic baggy that contained some suspected crack cocaine. ... I believe the net weight was 22.0 grams of cocaine base or crack cocaine.
Id. (emphasis added). Athough we recognized that “admissions to the court by a defendant during a guilty plea colloquy can be relied upon by the court at the sentencing stage,” we concluded that these casual references, without more, did not “amount[ ] to a knowing and voluntary admission that the cocaine base constituted crack.” Id. The government had the burden of showing by a “preponderance of the evidence that the sub *141 stance in question was actually crack.” Id. Because we concluded that the government had not met that burden, we vacated James’s sentence under the crack cocaine enhancement and remanded for resentencing.
Here, we conclude that the government did meet its burden but just barely. The government’s only evidence was the testimony of Officer Kane. Kane is assigned to the task force of the Philadelphia Drug Enforcement Administration and admits that he is not a chemist.
See
app. at 77a. The district court, nevertheless, permitted him to state his opinion about the identity of the controlled substance involved in this case based upon his years of experience as a police officer. “Courts imposing sentence are free to consider a wide range of relevant material.”
United States v. Deaner,
The substance seized from defendants did not contain sodium bicarbonate — a common residue in crack cocaine. See app. at 73a. However, Kane explained that the presence of that ingredient is not crucial “[I]t depends on the cooker and how precise he is in his measurements as to whether there would be sodium bicarbonate left behind after the crack cocaine cooking process is over.” App. at 74a. 2 However, no evidence was presented about the expertise of the person who “cooked” the drugs seized from defendants. 3
Kane stressed that the substance seized from defendants was packaged in “clear plastic vials with color caps” which is how crack is commonly packaged on the streets of Philadelphia. App. at 75a. He, therefore, concluded that this substance was in fact “crack cocaine,” see app. at 77a, and the strength of that conclusion was tested by cross examination.
Although the identity of the substance defendants possessed need only be established by a preponderance of the evidence, “the preponderance standard is not toothless. It is the district court’s duty to ensure that the Government carries this burden by presenting rehable and specific evidence.”
United States v. Lawrence,
*142 III.
Defendants next contend that the district court erred in concluding that the government had not breached their plea agreements. “Whether the government’s conduct violated the terms of the plea agreement is a question of law” to which this Court gives plenary review.
United States v. Wilder,
In Hernandez, the defendant pled guilty pursuant to a written agreement in which the government agreed to “recommend [that Hernandez receive] credit for acceptance of responsibility and a sentence at the low end of the guideline range.” Id. at 80. The agreement was amended in court by the Assistant U.S. attorney who stated on the record “that if Mr. Hernandez should provide substantial assistance to the Government, either I guess through truthful information and testimony if necessary, that the Government may make a motion for downward departure at sentencing.” Id. Following his guilty plea, Hernandez provided two types of assistance. “First, he gave the government a hand-drawn map that ostensibly showed where a stash of cocaine could be found.” Id. “Second, Hernandez provided the government with information (which the government insists was ‘stale’) concerning drug dealing and illegally possessed guns in the Corpus Christi area.” Id. The government argued that the assistance was not substantial and refused to move for a downward departure at Hernandez’s sentencing. He then appealed his sentence on grounds that the government had breached the plea agreement. “Considering the type of information that the government should have expected from a defendant like Hernandez, who had been incarcerated for over six months, [the court of appeals] f[ou]nd it difficult to conceive of what more Hernandez could have provided that would be substantial....” Id. at 82. It therefore vacated his sentence and remanded to the district court for a determination of what the parties intended as “substantial assistance.”
Here, the government concedes that the defendants did provide truthful and accurate information, but insists that the information was not “complete” as required under the plea agreements. Officer Kane testified that “[he] believe[d] it was truthful, the information they gave us, although I did not believe it was full or complete.” App. at 82a. “Because both of the defendants had been involved in the drag business, specifically crack cocaine for numerous years. ... the accumulation of intelligence that they would have gathered while in the business far exceeded what they were willing to tell us in the proffer.” App. at 83a. Kane’s suspicions are supported by the defendants’ conduct during the “debriefing” sessions. Defendants demanded that they be interviewed together, and, during the interview, “one brother or the other would begin talking about something and the other brother would tell him, no, ... we’re not going to tell them about that. Often times they would laugh at each other.” App. at 83a. From this testimony, the district court properly could conclude that the each defendant failed to provide “all information concerning his *143 knowledge of, and participation in the distribution of cocaine base and other crimes about which he has knowledge” as was required by the agreement. App. at 19a, 26a-27a.
We also agree with the district court that the government’s in-court clarification of the terms of the plea agreements did not in any way alter defendants’ obligation to provide complete information. In open court, the Assistant U.S. Attorney acknowledged that “it’s the Government’s expectation after the proffer that Mr. Roman, if the information he is able to provide proves truthful and accurate, that he would receive a downward departure motion and it would not be a barrier to receiving such a motion, simply that he could not engage in affirmative investigative techniques but that he solely may be able to provide historical information to the Government.” App. at 58a-59a. Defendants argue that, if they provided truthful, accurate, but incomplete historical information, the government was still obligated to move for a downward departure. See Appellant Br. at 16. (Appellant Oscar Roman)(“There is no ambiguity in that language ... Oscar Roman would receive a downward departure motion if the information he provided met two criteria — truthfulness and accuracy....”). We disagree. Instead, we believe that the district court correctly interpreted this statement to mean that “the fact that [the information defendants provided] was simply historical would not, in and of itself, prevent it from qualifying as substantial assistance.” App. at 143a. Therefore, we find no error in the district court’s determination that the government did not breach the plea agreement by refusing to file a downward departure motion.
IV.
Samuel Roman alleges error in the district court’s denial of his request for CJA funds to retain a psychiatrist. In appropriate cases a court can order that such funds be provided to assist an indigent defendant in preparing for sentencing.
Counsel for a person who is financially unable to obtain investigative, expert, or other services necessary for adequate representation may request them in an ex parte application. Upon finding, after appropriate inquiry in an ex parte proceeding, that the services are necessary and that the person is financially unable to obtain them, the court ... shall authorize counsel to obtain the services.
18 U.S.C. § 3006A(e)(l). However, a court should first “satisfy itself that a defendant
may have a plausible defense.” United States v. Alden,
Samuel Roman wanted a psychiatrist “to testify at sentencing in support of his motion for a downward departure ... based on mental and emotional conditions and diminished capacity.” Appellant Br. at 12 (Appellant Samuel Roman). His mental and emotional condition, he claimed, was “due to, (a) the murder of his father, (b) the fact that from the age of five years old, he grew up without a father, and (c) his extensive abuse of drugs and alcohol.” Appellant Br. at 15 (Appellant Samuel Roman).
Under the Guidelines, those factors do not warrant a downward departure. Section 5H1.4 of the Guidelines states that “[d]rug or alcohol dependence or abuse is not a reason for imposing a sentence below the guidelines.” U.S.S.G. § 5H1.4 (emphasis added). Section 5H1.12 states that “[l]aek of guidance as a youth and similar circumstances indicating a disadvantaged upbringing are not relevant grounds for imposing a sentence outside the applicable guideline range.” U.S.S.G. § 5H1.12 (emphasis added). Taken together, these sections demonstrate that the facts of his case did not warrant a downward departure. Accordingly, the district court did not abuse its discretion by denying Sam *144 uel Roman funds to retain a psychiatrist to testify in support of that departure.
He also claims that this denial “deprived him of his rights under the Due Process and Equal Protection clauses of the United States Constitution.” Appellant Br. at 12 (Appellant Samuel Roman). For this proposition, he cites
Ake v. Oklahoma,
V.
For the reasons set forth above, we will affirm defendants’ judgments of sentence entered on October 16,1996.
Notes
. Note D of section 2D 1.1 of the Sentencing Guidelines defines "cocaine base" as "crack.” " 'Crack' is the street name for a form of cocaine base, usually prepared by processing cocaine hydrochloride and sodium bicarbonate, and usually appearing in a lumpy, rocklike form.” U.S.S.G. § 2D 1.1 n.D.
.
See United States v. Sciarrino,
. It is certainly understandable that the government would not know who manufactured a given seizure of drugs, and we do not fault the government for not presenting that evidence. We mention the absence of such testimony because it reduces (but does not negate) the probative value of Kane’s explanation for the absence of sodium bicarbonate.
. We take this opportunity to express our concern over the manner in which the government chose to establish that the substance involved in this case was crack. We have previously emphasized the importance of correctly determining that a substance is crack because of the 100:1 sentencing ratio for cocaine base, as compared to cocaine, under the Sentencing Guidelines.
See James,
We have recently stated that an indictment need not identify the controlled substance at issue as the identity is a factor for sentencing, and not an element of the offense.
See United States v. Lewis,
