Opinion ID: 2997534
Heading Depth: 2
Heading Rank: 1

Heading: The Dog Alert

Text: As mentioned earlier, the crucial threshold issue is whether Bax’s alert, which linked Calhoun’s cash hoard to illegal drug activity, is entitled to any probative weight. Calhoun argues that it is not, citing what he describes as “the consensus that most U.S. currency in circulation in the United States (and specifically the Chicago area) is tainted 12 No. 02-2899 with cocaine” in levels detectable by drug dogs. Thus, assuming a large proportion of the currency in general circulation is tainted with enough cocaine to trigger a drug dog alert, such an alert would be virtually useless in establishing the necessary link to illegal drug activity justifying forfeiture. But it is a matter of some scientific debate whether dogs alert only to cocaine itself or rather to the odor of a cocaine byproduct, such as methyl benzoate. Thus the critical question is not whether most currency in general circulation is tainted with cocaine, but whether the cocaine itself is what triggers dog alerts to currency. If properly trained dogs alert to cocaine and not another substance or a byproduct of cocaine, then Calhoun’s argument is stronger—dog alerts to currency would have little or no probative weight if it can be shown that most currency is “innocently” tainted with detectable levels of cocaine. On the other hand, if dogs alert to methyl benzoate as opposed to cocaine per se, and the byproduct is volatile enough to evaporate from the currency within a short period, then a dog alert likely would be more probative because even assuming that most currency is tainted with particles of cocaine, dogs will not alert to it unless it contains the odor of methyl benzoate. Calhoun argues that even if dogs alert to methyl benzoate and not cocaine, the government must prove that the dog in question has been properly trained to alert only to the methyl benzoate, as opposed to something else, such as the currency itself. Thus, Calhoun challenges the evidentiary worth of any dog alert to currency and Bax’s reliability in particular. No. 02-2899 13
Calhoun relies principally on the work of Dr. Charles Mesloh.5 See Charles Mesloh et al., Sniff Test: Utilization of the Law Enforcement Canine in the Seizure of Paper Currency, 52 J. FORENSIC IDENT. 704 (2002) (“Sniff Test”). Dr. Mesloh’s article at first glance seems to support Calhoun’s currency contamination argument because it cites several studies indicating that 70-90% of circulated paper currency in major U.S. cities is contaminated with trace amounts of cocaine. See id. at 721-22; see also Adam Negrusz et al., Detection of Cocaine on Various Denominations of United States Currency, 43 J. FORENSIC SCI. 626, 626-29 (1998) (finding cocaine in amounts up to 10 micrograms per bill on randomly selected general circulation currency). Calhoun also cites caselaw, including from this circuit, which seems to adopt the currency contamination theory and concludes that dog sniffs are entitled to little or no probative weight. See United States v. $506,231 in U.S. Currency, 125 F.3d 442, 453 (7th Cir. 1997) (“[W]e are unwilling to take seriously the evidence of the post-seizure dog sniff. . . . Even the government admits that no one can place much stock in the results of dog sniffs because at least one-third of the currency in the United States is contaminated with cocaine in any event.”); Muhammed v. Drug Enforcement Agency, 92 F.3d 648, 653 (8th Cir. 1996) (holding that a dog alert is “virtually meaningless” because an “extremely high percentage of all cash in circulation in America today is contami- 5 Dr. Mesloh holds a Ph.D. in Public Affairs and is an assistant professor at Florida Gulf Coast University. Dr. Mesloh is a former police officer with wide experience and scholarship in the practical uses of canines in support of law enforcement, including dog sniff searches. Dr. Mesloh appears to have coauthored the cited article while he was a candidate for his Ph.D. 14 No. 02-2899 nated with drug residue”); United States v. $5000 in U.S. Currency, 40 F.3d 846, 849 (6th Cir. 1994) (same); United States v. U.S. Currency, $30,060.00, 39 F.3d 1039, 1042 (9th Cir. 1994) (same). A closer read of Dr. Mesloh’s article, however, reveals that it does not support Calhoun’s contention that “widespread contamination of currency at levels detectable by a drugdetection dog renders insupportable any inference that the most recent holder of the currency was involved with illegal narcotics activity.” Rather, Dr. Mesloh’s article merely provides practical and helpful recommendations to law enforcement agencies in the wake of apparent judicial adoption of the currency contamination theory. See, e.g., Mesloh et al., Sniff Test at 708 (questioning Ninth Circuit conclusion that, given 75-90% contamination rate of currency, “it is extremely likely a narcotics detection dog will positively alert when presented with a large sum of currency”) (citing $30,060, 39 F.3d at 1043). Indeed, Dr. Mesloh himself suggests that dog sniffs are reliable even if a large proportion of circulated currency is tainted by narcotics. See Mesloh et al., Sniff Test at 708 (noting that “recent research has shown that dogs will not alert on large amounts of currency[,]” and that “the drug odor on which the dogs are trained to alert dissipates over time, leaving only trace amounts on currency[.]”). Dr. Mesloh also cites scientific studies concluding that dogs likely do not alert to cocaine itself but rather to methyl benzoate. See id. at 708-09 (citing the research of Dr. Kenneth Furton). Dr. Mesloh acknowledges scientific findings that methyl benzoate “was found to evaporate rapidly from the surface of paper currency at a rate of approximately 90% in 120 minutes” and allows that “research does suggest that methyl benzoate may be one of the components of the odor that dogs are trained to detect.” Id. at 709. Thus, Dr. Mesloh concludes, these scientific findings “restore the credibility of the canine sniff[,]” id., contrary to No. 02-2899 15 the view expressed by the Ninth Circuit in $30,060 and by other courts. See, e.g., $30,060, 39 F.3d at 1042-43. Therefore, we do not read Calhoun’s own proffered empirical evidence as bolstering his currency contamination theory. The cited work of Dr. Mesloh6 proposes practical solutions to reduce the likelihood that a court will overturn dog alerts on the basis of the currency contamination theory. See Mesloh et al., Sniff Test at 715 (“[A]ny agency that is intent on conducting drug money forfeiture must be aware of its obligations to scientific rigor. . . . If the [recommended] policies are implemented and maintained, a department will ultimately stand to benefit from the value of the property that has been seized and from more effective and cost efficient defenses of the seizures during judicial review.”).
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.”).
Calhoun contends that there is no evidence that Bax is a reliable drug detector dog, and thus Bax’s alert to his cash No. 02-2899 21 is entitled to no probative weight. On this issue, however, we are satisfied that the record amply demonstrates Bax’s reliability. Bax is a certified narcotic detector dog, having received his certification in November 1997 upon completion of 400 hours of training with his handler, Officer Arrigo. Bax’s diploma indicates that he was qualified to detect marijuana, cocaine, and heroin; in 1999, Bax underwent recertification at which time he was certified to detect methamphetamine. During the performance of his duties in the years after certification, Bax racked up an impressive record. Drugs or currency were found after 97.6% of his alerts. Drugs were found after 70.1% of his alerts. Only five of Bax’s alerts (the remaining 2.4%) were unambiguous false positives, and none of those took place in the two years prior to the seizure of Calhoun’s cash hoard. These facts are reflected in the record and set forth in the government’s statement of material facts, and Calhoun disputed none of these facts in his opposition to summary judgment. But Calhoun now attacks Bax’s reliability by pointing to evidence that Bax conducted certification training with both actual cocaine and pseudococaine (which consists primarily of methyl benzoate). Furton et al., Novel Methods at 61 (“The active ingredient in . . . pseudococaine is actually methyl benzoate.”). According to Calhoun, “a dog’s training regimen will assure probativeness of future alerts to currency only if pseudococaine/methyl benzoate is the only material used during training.” Calhoun cites to some caselaw for this proposition and contends that Bax was not properly proofed to alert only to methyl benzoate, or somehow lacked adequate training generally. See, e.g., $22,474, 246 F.3d at 1216 (holding that a dog alert to currency was probative because the government offered evidence that “the dog was trained to, and would only, alert to the odor of a chemical by-product of cocaine called methyl benzoate”) (emphasis added); United States v. $10,700 in U.S. Cur22 No. 02-2899 rency, 258 F.3d 215, 230 (3d Cir. 2001) (declining to determine the evidentiary weight to be accorded dog alerts to currency because the government had not presented any evidence concerning the dog’s training or its degree of accuracy in detecting narcotics on currency). Thus, Calhoun argues that Bax’s record “does nothing to show that Bax has been trained to distinguish (or has otherwise shown the ability in practice to distinguish) recently tainted currency from currency in general circulation.” This is a distinction without meaning, however. For the reasons exhaustively set forth above, dogs apparently do not alert to cocaine at all, but rather to methyl benzoate. So it does not matter whether Bax was trained with actual cocaine and pseudococaine, because he was actually trained to detect and alert to the odor of methyl benzoate emanating from the cocaine and pseudococaine, not the odor of cocaine per se—which is impossible to detect in any event, due to its anesthetic qualities. Furton et al., Odor Signature at 331 (“When a dog is trained to alert to . . . drugs, . . . the canine is actually being trained to alert to a scent associated with the item rather than the item itself. . . . This is the basis of commercial training aids developed, such as pseudo cocaine, . . . which[ ] in fact[ ] contain no controlled substances but, rather, only the controlled substance odor.”); (Rose Aff. ¶ 2, Gov’t App. at 22.) And, as discussed, currency in general circulation, even if it is tainted, does not exude enough methyl benzoate to trigger a dog alert (unless the cash is very recently tainted and present in massive quantities) due to the substance’s high rate of evaporation. An alert to currency in most circumstances would indicate that the currency is not innocently tainted, but instead tainted through contact or close proximity to illegal narcotics. Equally unavailing is Calhoun’s suggestion that Bax might alert to general circulation currency itself (the smell of cash) even in the absence of the odor of methyl benzoate. No. 02-2899 23 Bax was certified to detect certain narcotics, not currency— and apparently there are dogs trained for that specific purpose. See Normal Lorenzo et al., Laboratory and Field Experiments Used to Identify Canis Lupus Var. Familiaris Active Odor Signature Chemicals from Drugs, Explosives, and Humans, 376 ANALYTICAL & BIOLANALYTICAL CHEMISTRY 1212, 1213 (2003) (listing various detector dog types). There is no indication in the record (nor does Calhoun offer any meaningful argument) to suggest that Bax alerts to general circulation currency itself or to some other substance or byproduct that may be on currency by virtue of innocent contamination—indeed, extensive research by Dr. Furton and Dr. Rose indicates that trained dogs do not alert to any byproduct of cocaine other than methyl benzoate. See Furton et al., Odor Signature at 331 (“None of the dogs tested alerted to by-products other than methyl benzoate. . . .”); Kenneth G. Furton et al., Identification of Odor Signature Chemicals in Cocaine Using Solid-Phase MicroextractionGas Chromatography and Detector-Dog Response to Isolated Compounds Spiked on U.S. Paper Currency, 40 J. CHROMATIC SCI. 147, 155 (2002) (“Identification”). In addition, as we previously have recognized, there is no need to “proof” a dog off currency when there is ample evidence to illustrate the dog’s reliability in the field. See, e.g., United States v. Limares, 269 F.3d 794, 798 (7th Cir. 2001) (“Whether you can confuse a drug-detection dog depends . . . on how dogs perform in practice, not, as Limares believes, how they were trained and ‘proofed off’ currency.”). Thus, we do not accept Calhoun’s contention that Bax is an “unsophisticated” narcotics detector dog, and Calhoun’s cited caselaw does not convince us otherwise. Calhoun cites $22,474 in support of his view that dogs must be shown to alert only to methyl benzoate as opposed to cocaine itself— a view resting on a faulty premise of which we have already disposed (cocaine per se has no odor). In fact, we read the Ninth Circuit’s reasoning in that case to be consistent with 24 No. 02-2899 the empirical information offered by the government— dogs alert to the odor of methyl benzoate, not to the minute particles of cocaine present on currency in general circulation. Cf. $22,474, 246 F.3d at 1216 (finding dog alert probative because of government evidence that “the dog would not alert to cocaine residue found on currency in general circulation[,]” but rather to methyl benzoate). Likewise, Calhoun’s citation to $10,700 does not carry the day. In that case, the Third Circuit attached no significance to a positive alert to currency because the government failed to present any evidence concerning the dog’s past training or accuracy. $10,700, 258 F.3d at 230. This is quite unlike the situation presented here, in which the government presented uncontroverted evidence demonstrating Bax’s qualifications and reliability in the field. Given these facts, we agree with the district court’s conclusion that Bax was a reliable detector dog at the time of his alert to Calhoun’s cash. Certainly we may assume that Bax is wrong on rare occasion, as evidenced by his handful of false positives over the years. But Bax’s high rate of success (drugs or currency were found after 97.6% of his alerts, and drugs were found after 70.1% of his alerts), coupled with the additional empirical information before us in this case, is more than adequate to indicate his reliability in this case. See Limares, 269 F.3d at 798 (“[E]ven if all alerts to currency are treated as false positives, [drug detection dog] Wendy has been right 62% of the time [as to the presence of drugs], enough to prevail on a preponderance of the evidence. . . .”) (emphasis in original).
In sum, on the evidence contained in the record as supplemented by empirical evidence, we conclude that Bax’s positive alert is entitled to probative weight in this case. The publicly available empirical information offered in this case supports the conclusion that no properly trained dog No. 02-2899 25 could have alerted to Calhoun’s cash hoard, which comprised 1700 individual bills, if it had contained only innocently tainted bills. As indicated earlier, at least 50,000 such bills would be necessary to trigger a dog alert (likely many more, given that Calhoun’s bills were stacked and bound in 29 separate bundles). In addition, the very ephemeral nature of the methyl benzoate byproduct of illicit cocaine makes it highly likely that Calhoun’s cash hoard was in very close proximity to large amounts of the drug within hours or days of Bax alerting to it.8