dissenting:
The Sixth Amendment’s Confrontation Clause bars “admission of testimonial statements of a witness who did not appear at trial unless he was unavailable to testify, and the defendant had a prior opportunity for cross-examination.” Crawford v. Washington, 541 U.S. 36, 53-54, 124 S.Ct. 1354, 158 L.Ed.2d 177 (2004). In this case testimonial statements (laboratory test results) of witnesses (laboratory technicians) who did not appear at trial were introduced against Dwonne Washington. Accordingly, I respectfully dissent from the majority’s holding that the admission of the test results did not violate Washington’s Confrontation Clause right. Unlike the majority, I conclude that (1) the test results are the hearsay statements of the laboratory technicians; (2) the statements are testimonial; and (3) the defendant, and not this court, must determine whether there would be value in cross-examining the technicians.
The laboratory test results in this case, which were offered to prove that Washington’s blood contained intoxicating levels of phencyclidine (PCP) and alcohol, were the hearsay statements of the technicians who ran the tests. The test results, although computer-generated, were produced with the assistance and input of the technicians *233and must therefore be attributed to the technicians. For this reason, the majority is mistaken in concluding that “[t]he raw data generated by the diagnostic machines [or computers] are the ‘statements’ of the machines themselves.” See ante at 230.
Courts consistently consider computer-generated assertions of fact as hearsay statements that are admissible only under one of the exceptions to the hearsay rule. See United States v. Blackburn, 992 F.2d 666 (7th Cir.1993) (computer printouts of lensometer readings); United States v. Enterline, 894 F.2d 287 (8th Cir.1990) (computer report identifying vehicle as stolen); United States v. Baker, 855 F.2d 1353 (8th Cir.1988) (laboratory analyses of controlled substances); United States v. DeWater, 846 F.2d 528 (9th Cir.1988) (breathalyzer test result); United States v. Hardin, 710 F.2d 1231 (7th Cir.1983) (computer-generated graph of data collected by law enforcement); United States v. McKinney, 631 F.2d 569 (8th Cir.1980) (blood test results); State v. Madorie, 156 S.W.3d 351 (Mo.2005) (breathalyzer test result); City of Helena v. Hoy, 248 Mont. 128, 809 P.2d 1255 (1991) (same). As these cases show, the majority is wrong in its claim that computer printouts or mechanical transmissions that do not directly transcribe the written or spoken words of humans are exempt from the hearsay rule.
In only one circumstance is a computer-generated assertion not considered the statement of a person: when the assertion is produced without any human assistance or input. In United States v. Hamilton, 413 F.3d 1138 (10th Cir.2005), one of two federal cases relied on by the majority, the Tenth Circuit concluded that the computer-generated header information that accompanied a pornographic image on the internet was not a hearsay statement. “Of primary importance to this ruling,” however, “[wa]s the uncontroverted fact that the header information was automatically generated by the computer ... without the assistance or input of a person.” Id. at 1142 (emphasis added). Similarly, in United States v. Khorozian, 333 F.3d 498 (3d Cir.2003), the other federal case cited by the majority, the Third Circuit determined that the transmission information on a faxed document was not a hearsay statement because it was automatically generated by the fax machine. But see United States v. Salgado, 250 F.3d 438 (6th Cir.2001) (stating that telephone numbers recorded and stored by computer were hearsay statements that were admissible under the business records exception); United States v. Linn, 880 F.2d 209 (9th Cir.1989) (same).
Unlike the header information on a web page or fax, computerized laboratory equipment cannot detect, measure, and record toxin levels in blood samples without the assistance or input of a trained laboratory technician. The toxicology-tests on Washington’s blood in this case were conducted by technicians at the Armed Forces Institute of Pathology. These technicians undergo extensive training before they are certified to perform the tests. A technician conducting a blood toxicology test must follow a “step-by-step procedure.” J.A. 48. He must, among other things, calibrate the testing instrument; withdraw the appropriate portion of blood from the larger sample; insert, without contamination, the smaller test sample into the instrument; initiate the test; and monitor the instrument while the test is in progress. Finally, as the record in this case reveals, the technician reviews and annotates the results and signs the report. In light of the significant role that the technician plays in conducting the test and generating accurate results, the results cannot be attributed solely to the machine. As a result, the toxicology test results must be considered statements of the labo*234ratory technicians for both evidentiary and Confrontation Clause purposes.1
The test results are testimonial statements, notwithstanding the majority’s argument to the contrary. The Supreme Court in Crawford, rather than specifically defining “testimonial,” provided examples that constitute the “core class of ‘testimonial’ statements.” 541 U.S. at 51, 124 S.Ct. 1354. Among these are “pretrial statements that declarants would reasonably expect to be used prosecutorially.” Id. The Court further clarified the meaning of “testimonial” in Davis v. Washington, - U.S. -, 126 S.Ct. 2266, 165 L.Ed.2d 224 (2006), stating that courts should also consider the “primary purpose” of the statement. A statement is not testimonial, for example, if its “primary purpose ... is to enable police assistance to meet an on-going emergency.” Id. at 2273. A statement is testimonial, on the other hand, “when the circumstances objectively indicate ... that the primary purpose of the [statement] is to establish or prove past events potentially relevant to later criminal prosecution.” Id. at 2273-74.
The laboratory test results in this case are testimonial as contemplated by Crawford and Davis. First, the laboratory technicians who conducted the blood tests should have expected that the results would be used for criminal prosecution. The sample of Washington’s blood that was sent to the testing laboratory was accompanied by a “Police Officer’s Report” that identified Washington by name, offense (DUI), and date of arrest. See United States v. Magyari, 63 M.J. 123, 127 (C.A.A.F. 2006) (stating that “lab results ... may become testimonial where a defendant is already under investigation, and where the testing is initiated by the prosecution to discover incriminating evidence”). Second, the primary purpose of the blood tests was to prove an essential element of the offense for which Washington was charged, specifically the presence of PCP and alcohol in his blood. For these reasons, the test results are testimonial. See State v. March, 216 S.W.3d 663, 666 (Mo.2007) (lab report identifying crack cocaine is testimonial); City of Las Vegas v. Walsh, 120 Nev. 392, 91 P.3d 591, 595 (2004) (affidavit of nurse who drew defendant’s blood is testimonial); State v. Moss, 215 Ariz. 385, 160 P.3d 1143, 1149 (Ct.App.2007) (“We conclude that the proposed testimony of [former laboratory director] reporting [defendant’s] blood test results would constitute testimonial evidence within the meaning of Crawford.”), People v. Rogers, 8 A.D.3d 888, 891-92, 780 N.Y.S.2d 393 (N.Y.App.Div.2004) (admission of blood alcohol test violated Confrontation Clause); Johnson v. State, 929 So.2d 4, 7 (Fla.Dist.Ct.App.2005) (“lab report prepared pursuant to police investigation and admitted to establish an element of a crime is testimonial hearsay”); State v. Crager, 164 Ohio App.3d 816, 844 N.E.2d 390, 397 (2005) (lab reports and DNA reports are testimonial if they “are pre-pared solely for prosecution”); State v. Miller, 208 Or.App. 424, 144 P.3d 1052, 1060 (2006) (lab report concluding urine contained methamphetamine is testimonial); cf. United States v. Oates, 560 F.2d 45, 80-81 (2d Cir.1977) (concluding, pre-Crawford, that admitting chemist report against the defendant could violate his Confrontation Clause right).2
The majority’s conclusion that the blood test results are not testimonial because *235they “relate[ ] solely to the present condition of the blood,” ante at 232, is not defensible. Again, according to Davis, the question is whether the primary purpose of the statement is to prove a past event relevant to prosecution. 126 S.Ct. at 2273-74. Here, U.S. Park Police Officer Gary Hatch took Washington to a hospital after his arrest, where a blood sample was taken. The sample was taken in an effort to prove that Washington’s blood contained PCP and alcohol at the time he was pulled over on the Baltimore-Washington Parkway. The government could only prove that Washington had intoxicants in his blood at the time of the stop by showing their continued presence shortly thereafter. Thus, although the test results show the levels of PCP and drugs in Washington’s blood at the time the sample was taken, the purpose of the test was to prove a past event relevant to prosecution.
Finally, it is not for the majority to say that “there would be no value in cross-examining the lab technicians.” Ante at 230. A defendant’s right to confront witnesses against him does not depend on whether a court believes that cross-examination would be useful. Cf. Crawford, 541 U.S. at 62, 124 S.Ct. 1354 (“Dispensing with confrontation because testimony is obviously reliable is akin to dispensing with jury trial because a defendant is obviously guilty.”). The strategic decision of whether to cross-examine a laboratory technician is one for the defendant to make. Although in many cases a defendant may choose not to exercise this right, cross-examination of laboratory technicians may be useful in some instances. Forensic test reports are not always accurate. Testing errors are sometimes caused by technician inexperience, sample contamination, failure to follow laboratory protocols, or breaks in the chain of custody. Furthermore, on rare occasions laboratory technicians have “engage[d] in long-term systematic, and deliberate falsification of evidence in criminal cases.” Pamela R. Metzger, Cheating the Constitution, 59 Vand. L.Rev. 475, 499 (2006). In one notorious case, a forensic serologist at the West Virginia Department of Public Safety falsified hundreds of forensic tests between 1979 and 1989. Id. The best way to expose errors or falsification in testing is through cross-examination of the laboratory technician. See Crawford, 541 U.S. at 61, 124 S.Ct. 1354 (stating that the reliability of testimony is best determined “in the crucible of cross-examination”).
In sum, the laboratory test results admitted against Washington were testimonial statements. Washington therefore had the right to confront and cross-examine the technicians who conducted the tests on his blood. Because Washington was not provided this opportunity, and the government does not contend that the witnesses were unavailable, his Confrontation Clause right was violated.
. The government does not contend that the test results are not statements. At trial it conceded that the results are hearsay statements, but argued that they are admissible under the business records exception. See Fed.R.Evid. 803(6).
. I recognize that laboratory test results are not always testimonial. Many tests are con*235ducted for purposes other than gathering evidence for a criminal prosecution, and there are circumstances when the technician does not have any reason to believe that the results will be used in a prosecution. The results of laboratory tests performed with respect to a person not suspected of illegal activity, for example, would not be testimonial because the technician performing the test would not have reason to believe that the results would be used at trial. See Magyari, 63 M.J. at 127 ("Because the lab technicians were merely cataloging the results of routine tests, the technicians could not reasonably expect their data entries would 'bear testimony’ against the [defendant].”). Similarly, tests performed in the course of medical treatment would not be testimonial so long as the primary purpose of the tests was to assist in the treatment of the patient.