delivered the opinion of the Court.
A special court-martial composed of officer members convicted appellant, contrary to his pleas, of one specification of wrongful use of marijuana, in violation of Article 112a, Uniform Code of Military Justice, 10 USC *371§ 912a. The adjudged and approved sentence provides for a bad-conduct discharge and reduction to the lowest enlisted grade. The Court of Criminal Appeals affirmed the findings and sentence in an unpublished opinion.
This Court granted review of the following issue:
WHETHER THE MILITARY JUDGE ERRED WHEN HE DENIED APPELLANT’S REQUEST FOR A GOVERNMENT URINALYSIS EXPERT TO ASSIST IN HIS DEFENSE.
We hold that the military judge did not abuse his discretion, for the reasons set out below.
Factual Background
The charges against appellant were based on a positive urinalysis, in which appellant’s sample contained 16 nanograms per milliliter of the metabolite of marijuana, 1 nanogram over the Department of Defense cutoff for reporting samples as positive. Before trial, defense counsel submitted a request to the convening authority for the production of Dr. William Manders, a forensic toxicologist, to testify concerning passive inhalation and innocent ingestion. Trial counsel recommended that the request be denied, on the ground that a suitable substitute was available from the Naval Drug Screening Laboratory, Jacksonville, Florida.
When the court-martial convened, the convening authority had not yet acted on the request. Defense counsel renewed her request at an Article 39(a)1 session before the military judge. The parties stipulated that Dr. Manders would testify that “both innocent ingestion and passive inhalation could lead to the positive test for THC, the metabolite found in marijuana, based on the levels found in the sample submitted by Petty Officer Short.”
Defense counsel asserted at trial that the government witnesses would not testify that passive inhalation could produce marijuana metabolites at the level of 16 nanograms per milliliter. Trial counsel disputed her assertion and argued that the Government was able to produce an adequate substitute for Dr. Manders.
As the Article 39(a) session progressed, defense counsel broadened the scope of her request for assistance. She requested “the opportunity to have somebody, who is not employed by the drug lab, assess the chain of custody and procedures which were used by the drug lab.” She argued that “[i]t is unlikely that an employee of the drug lab is going to point out deficiencies or problems in the procedures used.” The military judge denied the motion to compel production of Dr. Manders as not ripe for resolution, since the convening authority had not yet acted. The court-martial then recessed on May 31, 1995.
When the court-martial reconvened on August 8, 1995, defense counsel filed a motion for expert assistance requesting “independent (i.e., unaffiliated with the Naval Drug Screening Laboratory, Jacksonville) expert assistance.” She asserted that the independent expert assistance was needed for the following purposes: “(a) to assist defense in understanding the scientific evidence (b) identifying problems with the scientific evidence and (c) preparing effective cross-examination of the government witness regarding the scientific evidence.”
In support of her expanded request, defense counsel stated the following:
The defense counsel in this case has no background in chemistry beyond basic high-school chemistry. Moreover, defense counsel does not have the knowledge of the drug-testing system used at NDSL Jax which would enable her to effectively cross-examine an expert in that area. The Standard Operating Procedure manuals are so voluminous and technical that defense counsel is unable to develop the required expertise independently.
The Government will be assisted in interpretation and presentation of its evidence by the expert scientific knowledge, opinions, and testimony of Mr. Cary Hall, an expert from NDSL Jax. The Executive Officer of NDSL Jax has already stated *372that the command has a policy to “not allow” their personnel to “testify against each other” in courts-martial.
During argument on defense counsel’s expanded request, trial counsel conceded that appellant was entitled to expert assistance, but would not concede that he was entitled to an independent expert, unaffiliated with the Navy Drug Screening Laboratory. Trial counsel asserted that adequate assistance was available from Mr. Cary Hall, “an independent and objective expert.” When defense counsel disputed trial counsel’s assertion that Mr. Hall was “impartial,” the military judge asked her, “Did you have an opportunity to talk with Mr. Hall yourself?” She responded, “Sir, I have not talked to him, nor do I intend to.”
Before ruling on the defense request for assistance, the military judge offered the following advice:
First let me say that one of the things that I certainly would encourage the defense counsel to do in this case, or any case, when it deals with a certain area of specificity or expertise, would be to call other defense counsel who have had experience in handling cases involving the drug labs and urinalyses in the past because they can provide assistance to you in how to go about litigating these cases, and there are a number of people on active duty in the naval service that are available to assist you in preparing a defense for this kind of case.
The military judge found that Mr. Hall was available “to explain to defense counsel the meaning of the scientific reports involved in this case, to interpret and explain the standard operating procedure manuals and regulations applicable to the drug lab and the Department of the Navy drug testing.” He found further that “Mr. Hall is made equally available to both the Government and defense and will explain the urinalysis lab testing process fully and completely, without shading his testimony to favor either side in this case.” Finally, he found that “Mr. Hall will readily fully explain the urinalysis testing procedures at the Navy Drug Screening Lab, Jacksonville, Florida, including any difficulties, errors, or problems that the lab may have encountered generally or specifically with regard to the testing of the accused’s sample.”
The military judge then recited the defense burden of showing necessity and ruled that the defense had failed to meet that burden. Accordingly, he denied the motion for independent expert assistance.
The court-martial then recessed on August 8 and reconvened on August 15 for the trial on the merits. Mr. Hall testified for the prosecution regarding appellant’s positive urinalysis. Defense counsel cross-examined Mr. Hall extensively about testing methods, control procedures, the likelihood of false positives, and the chain of custody. Defense counsel elicited admissions from Mr. Hall that some Navy laboratories, including the laboratory that tested appellant’s sample, had experienced problems with testing accuracy. Defense counsel also elicited an admission that appellant’s nanogram level was consistent with unknowing ingestion.
Appellant testified in his own defense and repeatedly denied knowingly using marijuana. He testified that he did not know why the marijuana metabolite was found in his urine. He testified that he was “very positive that [he] did not use, ingest, marijuana knowingly in any shape or form.”
Discussion
RCM 703(d), Manual for Courts-Martial, United States (1998 ed.),2 authorizes the employment of experts at government expense when their testimony would be relevant and necessary, and when the Government cannot or will not provide an adequate substitute. An accused is not automatically entitled to an independent expert in every urinalysis case. However, upon a proper showing of necessity, an accused is entitled to expert assistance to prepare a defense. United States v. Burnette, 29 MJ 473, 475 *373(CMA 1990). An accused is not, however, entitled to a specific expert of his own choosing. “All that is required is that competent assistance be made available.” Id. As this Court observed in United States v. Garries, 22 MJ 288, 290-91 (1986), “In the usual case, the investigative, medical, and other expert services available in the military are sufficient to permit the defense to adequately prepare for trial.”
In United States v. Gonzalez, 39 MJ 459, 461 (1994), this Court adopted a three-pronged test for showing that expert assistance is necessary:
First, why the expert assistance is needed. Second, what would the expert assistance accomplish for the accused. Third, why is the defense counsel unable to gather and present the evidence that the expert assistant would be able to develop.
In United States v. Kelly, 39 MJ 235, 238 (1994), this Court stated that “[d]efense counsel are expected to educate themselves to attain competence in defending an issue presented in a particular case,” using “a number of primary and secondary materials” that are readily available. See e.g., E. Imwinkelried, The Methods of Attacking Scientific Evidence (2d ed. 1992), cited in Kelly, supra at 238. Due process requires that the accused be given the “basic tools” necessary to present a defense, but defense counsel is responsible for doing his or her homework. See Kelly, supra at 237, citing Ake v. Oklahoma, 470 U.S. 68, 77, 105 S.Ct. 1087, 84 L.Ed.2d 53 (1985).
We review the military judge’s decision on a request for expert assistance for abuse of discretion. See United States v. Washington, 46 MJ 477, 480 (1997), citing Garries, supra at 291.
Applying the foregoing principles, we hold that the military judge did not abuse his discretion by denying the request for independent expert assistance. The defense offered nothing to show that appellant’s case was not “the usual case.” See Garries, supra at 290-91.
With respect to her original request for expert assistance to establish passive inhalation or innocent ingestion, defense counsel failed to show necessity. Although she refused to talk to Mr. Hall and insisted that he could not support the defense theory of innocent ingestion, the record reflects the contrary. Defense counsel made her point in cross-examination of Mr. Hall, when he agreed that appellant’s urinalysis results were consistent with passive inhalation or innocent ingestion.
With respect to defense counsel’s attempt to expand her request, we hold that the military judge did not abuse his discretion. He recognized defense counsel’s attempt for what it was: an assertion that she did not know how to try a urinalysis case. He responded appropriately by suggesting that defense counsel consult with more experienced counsel and talk to Mr. Hall about the scientific procedures involved in this case. Defense counsel responded that she would not talk to Mr. Hall, even though basic trial preparation would require that he be interviewed, because he was expected to testify on the merits.
The record of trial does not reflect whether defense counsel heeded the military judge’s advice. In fact, nowhere in the record did defense counsel describe what attempts she made to educate herself, before or after the military judge’s gratuitous advice.
While Mr. Hall could not satisfy defense counsel’s request for an independent expert, the military judge gave defense counsel “the tools potentially to gather evidence to lay a foundation for the necessity of an independent [assistant].” Gonzalez, 39 MJ at 461, citing United States v. Kelly, supra. After having a week to heed the military judge’s advice, defense counsel did not renew her request for expert assistance when the court-martial convened for the trial on the merits.
Even with the benefit of post-trial hindsight, appellant still did not satisfy the Gonzalez test. The record reflects that defense counsel cross-examined Mr. Hall exhaustively, elicited potentially damaging admissions about problems with testing accuracy in his *374laboratory, and elicited scientific support for the defense theory of innocent ingestion.
In sum, there is nothing in this record to show necessity for an independent expert and nothing to show that the trial was rendered unfair by the military judge’s refusal to order that an independent expert be provided. Accordingly, we hold that the military judge did not abuse his discretion.
Decision
The decision of the United States Navy-Marine Corps Court of Criminal Appeals is affirmed.
. Uniform Code of Military Justice, 10 USC § 839(a).
. This Manual provision is the same as the provision that was in effect at the time of appellant’s offense and court-martial.