ELSAG data and conducting criminal history check not used by court to determine if extending stop was proper


On February 12, 2020, Louisiana State Police Sergeant Brett McKee was watching eastbound traffic while stationed on the shoulder of I-10. As a member of the interdiction patrol, he was looking for traffic violations and other, more serious criminal activity, including drug trafficking. McKee had served on the patrol for two years and with the Louisiana State Police for twelve.

At some point that night, McKee observed a Toyota SUV driving about two to three miles above the speed limit. The driver abruptly braked as he passed, even though there was no traffic. McKee considered this to be “stress-induced behavior” —that is, behavior that’s atypical of a law-abiding driver—and began following the car. The car drifted over the white fog line in violation of Louisiana law, so McKee pulled it over.

McKee told the driver, Trevor Daniel, that he was being stopped for improper lane usage and asked him to exit the vehicle. Daniel complied but explained that the car, which he said was a rental, braked suddenly because of its adaptive cruise control. McKee and Daniel walked to the driver’s side so that Daniel could get his ID and then around to the passenger’s side so that Daniel could get the rental agreement.

While walking around the car, McKee saw four to five bags in the back, large bags and a lot of trash, including a bunch of drinks and fast food. He commented that it looked like Daniel had been on the road. Daniel said he had a security business and, seemingly losing track of what he was doing, handed McKee a random paper and his entire wallet, rather than just his ID.

McKee then asked Daniel about his business-related travel. Daniel responded vaguely, saying that he had a client “down there.” When McKee twice followed up, Daniel clarified that he was traveling from “Texas” and then, after some stuttering, “Sugarland.” McKee asked Daniel when he went to Sugarland. Daniel hesitated, asked McKee what day it was (Wednesday), and then said that he went to Sugarland on Monday.

McKee and Daniel continued to talk while McKee looked over Daniel’s ID and rental agreement. In response to McKee’s questions, Daniel said that he did not have a gun in the car and that he was still in the “talking stage” with a potential client in Sugarland. He told McKee that he started his security business when he got out of the military and, when McKee asked him which branch he served in and for how long, he answered quickly and confidently.

About four and a half minutes into the stop, McKee told Daniel that he was going to his car to run computer checks. McKee used a program called ELSAG, a license plate reader that tracks when a vehicle passes by certain cameras, to see where Daniel’s car had traveled. The ELSAG database showed that Daniel’s car had passed cameras far south of Sugarland, near the Mexico border. McKee’s criminal-history check revealed that Daniel was a convicted felon.

McKee returned to Daniel and asked whether he had traveled anywhere besides Sugarland, whether anyone else had driven the car, and whether the car contained any illegal substances. Daniel responded “no” to all. Daniel then denied McKee’s request to search the vehicle. At that point, about ten minutes into the stop, McKee contacted one of the U.S. Border Patrol’s dog handlers to request a dog sniff. The dog handler and dog arrived about four minutes later. The dog conducted a “free air sniff” around the vehicle and alerted to the driver’s side door. The officers subsequently searched the vehicle and found a firearm and 25 kilograms of cocaine.

Daniel was charged by indictment with possessing with the intent to distribute five or more kilograms of cocaine in violation of 21 U.S.C. §§ 841(a)(1), (b)(1)(A). He later moved to suppress the evidence seized during the traffic stop, arguing that (1) McKee lacked reasonable suspicion to extend the stop by conducting the ELSAG and criminal-history checks and arranging a dog sniff and (2) the dog’s alert did not give probable cause to search his car. The motions were denied.

Daniel pleaded guilty but preserved the right to appeal the district court’s denial of his motion to suppress. The district court sentenced Daniel to 120 months in prison and five years of supervised release. Daniel timely appealed. The 5th affirmed.


A. Extending stop

We analyze the constitutionality of a traffic stop under the two-step test from SCOTUS Terry v. Ohio, 392 U.S. 1 (1968). First, we determine whether the stop was justified at its inception. If it was, we determine whether the officer’s subsequent actions were reasonably related in scope to the circumstances that justified the stop of the vehicle in the first place. If the officer develops reasonable suspicion of additional criminal activity during his investigation of the circumstances that originally caused the stop, he may further detain the car’s occupants for a reasonable time while appropriately attempting to dispel this reasonable suspicion.

Daniel concedes that Terry’s first prong is satisfied because the initial traffic stop for improper lane usage was justified. But he argues that, under Terry’s second prong, McKee lacked reasonable suspicion to extend the stop by searching the ELSAG database, checking his criminal history, and arranging a dog sniff.

Neither party cites, nor have we have found, any published cases from our court that address whether a criminal-history check and ELSAG search fit within a traffic stop’s original mission. In two unpublished cases, we have assumed they do, but without confronting the question directly. See Solis and Rodriguez-Flores. But see United States v. Frazier, 30 F.4th 1165 (10th Cir. 2022) (The license plate reader search plainly exceeded the scope of the stop’s traffic-based mission).

We need not weigh in today because we conclude that McKee already had a reasonable suspicion that Daniel was engaging in other criminal activity by the time he ran the checks and requested the dog sniff.

McKee testified to, and his body-camera footage confirms, specific and articulable facts that gave rise to a reasonable suspicion that Daniel was engaged in other criminal activity. First, McKee observed that Daniel was traveling on I-10, which he knew from years of experience is a major drug-trafficking corridor. Travel along known drug corridors is a relevant—even if not dispositive—piece of the reasonable suspicion puzzle. See Smith.

Second, McKee testified that Daniel appeared nervous while driving. McKee saw Daniel brake “abruptly” when passing his car, even though there was no traffic around and he wasn’t speeding, and then drift over the fog line—two driving behaviors that, according to McKee, could suggest that Daniel was nervous about being near an officer because of criminal activity. See Gonzales (concluding that the officer had a reasonable suspicion of criminal activity in part because, when Gonzales passed his marked patrol vehicle, Gonzales tapped his breaks even though he was not speeding).

McKee testified that Daniel continued to act nervous and evasive after McKee pulled him over. While walking around Daniel’s car, McKee noticed the trash and commented that Daniel must have been on the road for a while. McKee testified that Daniel chuckled, got really anxious and lost function of what he was doing. When McKee asked for Daniel’s rental agreement, Daniel instead tried to give McKee his whole wallet and then gave McKee the wrong document. In addition, when McKee asked where Daniel was traveling from, Daniel at first answered down there, and only after McKee twice followed up did he say “Texas” and then, finally, “Sugarland.” McKee testified that, from his experience, Daniel’s vague and delayed responses suggested that he either didn’t know where he was coming from or he was trying to hide where he was coming from. And, by contrast, Daniel responded without hesitation to McKee’s questions about his military service. Nervous, evasive behavior, such as Daniel’s here, is a pertinent factor in determining reasonable suspicion. See SCOTUS Illinois v. Wardlow, 528 U.S. 124 (2000).

Third, Daniel told McKee that he arrived in Sugarland only two days prior—a timeline that McKee testified was contradicted by the trash and four to five large duffel bags that he saw in Daniel’s rental car. See Williams (noting that inconsistent or implausible answers to questions can support reasonable suspicion). The trash signaled to McKee that Daniel was instead traveling a . . . long distance without stopping or . . . going somewhere, turning around and coming right back, such as to pick up and then deliver a product. Likewise, the four to five duffel bags struck McKee as a lot of luggage for one person just for a short two-day trip.

Daniel argues that McKee’s observations had innocent explanations. However, to form a reasonable suspicion, McKee did not need to eliminate all reasonable possibilities of legal activity. We may not consider the relevant factors in isolation from each other and must instead evaluate the totality of the circumstances known to McKee. Accordingly, to confirm or dispel that suspicion, McKee could constitutionally extend the stop to conduct ELSAG and criminal-history checks and to request a dog sniff.

B. Search of car

We now turn to whether the dog alert gave McKee probable cause to search Daniel’s car.

When a dog’s alert is the purported basis for probable cause, the question—similar to every inquiry into probable cause—is whether all the facts surrounding a dog’s alert, viewed through the lens of common sense, would make a reasonably prudent person think that a search would reveal contraband or evidence of a crime. See SCOTUS Florida v. Harris, 568 U.S. 237 (2013). Daniel bears the burden of presenting any evidence of unreliability rebutting this presumption.

Here, the dog’s handler testified that the dog was certified annually by a U.S. Border Patrol K-9 instructor to detect cocaine and other drugs. The government has thus made a prima facie showing that the dog is reliable, and we may presume that its alert established probable cause. Daniel, however, argues that the dog sniff was unreliable because the dog (1) alerted by the driver’s side door, not the back hatch where the drugs were later found; (2) had twice alerted in the field when no drugs were present; and (3) had performed only twelve field searches over the past three years.

All of Daniel’s arguments fail. That the dog alerted to the driver’s side door does not indicate that the dog was unreliable—rather, as the dog’s handler testified, the dog was trained to alert to the smell of drugs, and the driver’s side had an open window from which the dog could have picked up the scent. Same for the dog’s two false positives during prior field searches. Field data may markedly overstate a dog’s real false positives because, for example, the dog may have smelled the residual odor of drugs previously in the vehicle.

The better measure of a dog’s reliability thus comes away from the field, in controlled testing environments. Accordingly, the dog’s two false positives, over the course of at least twelve searches, have relatively limited import. Regardless, the dog’s 83.3% field success rate assures us that its alert reflected at least a fair probability that contraband would be found, which is all that’s required for probable cause. Finally, we are unconcerned by the number of field searches that the dog had previously performed. The dog was certified annually, the dog and its handler had worked together for three consecutive years, and there were no signs that McKee or the handler cued the dog or were working under unfamiliar conditions. Thus, this “sniff is up to snuff.”

Because the dog’s certification establishes its reliability and Daniel fails to undermine that showing, we agree with the district court that the dog’s alert gave McKee probable cause to search Daniel’s car.