Opinion ID: 2997534
Heading Depth: 3
Heading Rank: 2

Heading: The Government’s Empirical Evidence

Text: Assuming as true that most currency is contaminated by trace amounts of cocaine, the studies cited by the government (and in part by Dr. Mesloh) directly address whether dogs alert to cocaine itself or to methyl benzoate. The authors of these studies hold advanced scientific degrees and have extensive experience in chemistry and forensic toxicology—fields that seem especially relevant to our analysis. Stefan Rose, for example, is an M.D. with years of research and training in the field of forensic toxicology and is a member of the faculty at Florida International University. Kenneth Furton holds a Ph.D. in analytical chemistry, has years of experience in the study of odor signatures, and is 6 Although his academic background is in public affairs, Dr. Mesloh is an experienced former law enforcement professional and former police dog handler, which lends some weight to his practical recommendations regarding methodology as discussed below. 16 No. 02-2899 a former chair of the chemistry department at Florida International University. Since 1993, both men have conducted extensive research on the scientific aspects of dog sniffs and have been retained to offer expert opinions on the subject in both state and federal courts. See, e.g., United States v. $242,484.00, 389 F.3d 1149, 1165 n.9 (11th Cir. 2004) (en banc); United States v. $22,474.00 in U.S. Currency, 246 F.3d 1212 (9th Cir. 2001) (see Rose Aff., Gov’t App. at 21); United States v. One Lot of U.S. Currency Totalling $14,665, 33 F. Supp. 2d 47, 58 n.9 (D. Mass. 1998); People v. Puertas, No. 224173, 2002 WL 31160304,  (Mich. Ct. App. Sept. 27, 2002) (unpublished) (per curiam). Both scientists have criticized the currency contamination theory and its uncritical adoption by courts. See, e.g., Kenneth G. Furton et al., Odor Signature of Cocaine Analyzed by GC/MS and Threshold Levels of Detection for Drug Detection Canines, 14 CURRENT TOPICS IN FORENSIC SCI. 329, 329 (1997) (“Odor Signature”) (“These conclusions are alarming in light of the fact that there are no definitive peer-reviewed studies determining the ‘range of a drug dog’s detection capability’ to cocaine nor are there any statistically significant determinations of the degree and extent of cocaine contamination on U.S. currency.”) (critiquing the Ninth Circuit’s analysis in $30,060 and the sources cited therein). The research of Dr. Furton and Dr. Rose established “to a reasonable scientific certainty that a narcotics detection dog alerts to the odor of methyl benzoate as the dominant odor of illicit cocaine, and not to cocaine itself.” (Aff. of Dr. Rose, Gov’t App. at 21; see also Furton et al., Odor Signature at 331.) In addition, the research indicates that dogs do not alert to byproducts other than methyl benzoate and would not alert to synthetic “pure” cocaine unless methyl benzoate was added. See Kenneth G. Furton et al., Field and Laboratory Comparison of the Sensitivity and Reliability of Cocaine Detection on Currency Using Chemical Sensors, Humans, K-9s and SPME/GC/MS/MS Analysis, in No. 02-2899 17 INVESTIGATION AND FORENSIC SCIENCE TECHNOLOGIES 41, 42 (Kathleen Higgins ed., 1999) (“Field Comparison”). Indeed, it seems that dogs cannot smell cocaine at all because the narcotic acts as an anesthetic that deadens olfactory senses. (Rose Aff. ¶ 2, Gov’t App. at 22) (“[C]ocaine is a local anesthetic and as such blocks the transmission of nerve impulses. Therefore, cocaine should block the transmission of olfactory . . . nerve fibers resulting in non-detection.”). In addition, methyl benzoate is highly volatile and evaporates at an exponential rate from tainted currency, so currency recently exposed to cocaine and returned to general circulation will quickly lose any detectable odor of methyl benzoate, even if the particles of cocaine remain. Furton et al., Field Comparison at 46; see also Kenneth G. Furton et al., Novel Sample Preparation Methods and Field Testing Procedures Used to Determine the Chemical Basis of Cocaine Detection by Canines, in FORENSIC EVIDENCE ANALYSIS AND CRIME SCENE INVESTIGATION 56, 58 (John Hicks et al. eds., 1997) (“Novel Methods”) (“Whereas the parent cocaine molecule is non-volatile and can remain [on] currency for long periods of time, . . . methyl benzoate dissipate[s] quickly . . . .”). A single cocaine-tainted bill will lose 90% of the odor of highly volatile methyl benzoate through evaporation within two hours of its removal from the presence of cocaine, but will lose the odor more slowly if stacked with other bills. Furton et al., Odor Signature at 332 (concluding that thirty stacked tainted bills lose less than 10% of the methyl benzoate odor in the span of two hours); (Rose Aff. ¶ 2, Gov’t App. at 22 (“The more closed the environment, the slower the rate of evaporation and the longer the smell remains. One would expect that currency involved in the recent transaction of significant amounts of illicit cocaine and bundled would retain the odor of methyl benzoate for days and weeks after the exposure. . . .”).) Dr. Furton and Dr. Rose undertook some 200 field and laboratory trials and ultimately concluded that dogs do not 18 No. 02-2899 alert to innocently tainted currency in general circulation because the amount of cocaine and methyl benzoate is too small for detection. (Cf. Rose Aff. ¶ 1, Gov’t App. at 21 (“[A] positive alert to U.S. currency by a properly trained . . . canine indicates that the currency had recently . . . been in close or actual proximity to a significant amount of narcotics, and is not the result of any alleged innocent environmental contamination of circulated U.S. currency by microscopic traces of cocaine.”).) The research indicated that, in contrast to the levels found on general circulation currency, the “threshold level of cocaine and methyl benzoate required for a canine to signal an alert was substantial and reproducible7.” Furton et al., Odor Signature at 332. As Dr. Furton and Dr. Rose conclude: Calculation from the amount of methyl benzoate required for a reliable detector dog alert (>85% [detection success] at 10 [micrograms]), the amount of methyl benzoate observed in street cocaine sample[s,] . . . and the diffusion rates of methyl benzoate from individual bills (ca. 10% remaining after 2 hours) indicate a required amount of recently contaminated cocaine residue of ca. 500 [milligrams] cocaine (initially). Furton et al., Field Comparison at 46. This required amount is “50,000 higher than the amount reported on circulated currency (ca. 10 micrograms/bill).” Id. at 46. Therefore, generously assuming that all bills in general circulation are tainted by 10 micrograms of cocaine, it would take at least fifty thousand bills to generate enough methyl benzoate to 7 The research of Dr. Furton and Dr. Rose also indicates that methyl benzoate is always associated to some degree with cocaine. See Furton et al., Odor Signature at 332. Pharmaceutical grade or pure cocaine contains only trace amounts of methyl benzoate, but illicit cocaine contains far more due to impurities. See Furton et al., Novel Methods at 58, 62; Furton et al., Field Comparison at 46. No. 02-2899 19 trigger a dog alert. And, as Dr. Furton and Dr. Rose point out, “the odor produced by contaminated bills stacked together does not increase proportionally to the number of bills, but rather is a function of the available surface area” of the bills. Id. This indicates that stacked or bundled bills, which obviously have less contaminated surface area exposed to the air, would exude a correspondingly smaller odor signature and the 50,000 figure therefore may be too small by orders of magnitude when tainted bills are bundled together (although stacked bills do retain the methyl benzoate for longer periods). Cf. id. at 45. In sum, the research led Dr. Furton and Dr. Rose to conclude that “[o]verall, the scientific results indicate that circulated currency, innocently contaminated with [microgram] quantities of cocaine would not cause a properly trained detection canine to signal an alert even if very large numbers of bills are present.” Id. at 46. Given the apparently rigorous empirical testing giving rise to this conclusion, it is likely that trained cocaine detection dogs will alert to currency only if it has been exposed to large amounts of illicit cocaine within the very recent past. As a result (and contrary to Calhoun’s assertions), it seems that a properly trained dog’s alert to currency should be entitled to probative weight. Likewise, we find the dog sniff caselaw cited by Calhoun either distinguishable or simply unpersuasive with regard to whether dog alerts to currency are entitled to probative weight. The conclusions reached in these cases rest on uncritical adoption of the currency contamination theory. In at least some of these cases, even the government seemed to assume the truth of the currency contamination theory. See, e.g., $506,231, 125 F.3d at 453 (case in which the government not only did not contest the currency contamination theory, it allowed that “no one can place much stock in the results of dog sniffs because at least one-third of the [U.S.] currency . . . is contaminated with cocaine . . . .”). 20 No. 02-2899 More recently, however, courts have taken the approach suggested by Dr. Furton and Dr. Rose and moved away from unquestioning acceptance of the currency contamination theory. As Calhoun himself concedes, “the federal courts have become more open-minded toward dog alert evidence.” See, e.g., $242,484, 389 F.3d at 1165-66 & n.9 (declining to “write the [currency contamination] theory into the law of [the Eleventh] [C]ircuit” and disagreeing with district court conclusion that probative value of dog alert to currency was weak, because “no one with any expertise testified in support of [the claimant’s] ever-lasting scent, global contamination theory”); United States v. $22,474.00 in U.S. Currency, 246 F.3d 1212, 1216 (9th Cir. 2001) (distinguishing earlier Ninth Circuit decisions that adopted the currency contamination theory because, unlike in the earlier cases, “the government presented evidence that the dog would not alert to cocaine residue found on currency in general circulation. Rather, the dog was trained to, and would only, alert to the odor of . . . methyl benzoate[, and] . . . unless the currency [the defendant] was carrying had recently been in the proximity of cocaine, the detection dog would not have alerted to it”). We therefore conclude that the empirical information provided in this case indicates that dog alerts to currency should be entitled to probative weight. Cf. Furton et al., Odor Signatures at 332 (“[T]here is no valid scientific basis for the theory that innocently contaminated currency contains sufficient quantities of volatile chemicals to signal an alert from a properly trained drug detector dog. Therefore, an alert to a specimen (including money) . . . indicates that the item contains a significant quantity of narcotic odor.”).