delivered the Opinion of the Court.
¶1 Trooper Joseph Ynostroza stopped John Cox for driving in the left lane. During the stop, the Trooper observed several factors that led him to suspect that there might be evidence of illegal activity in the trunk of the vehicle, including the fact that his canine alerted to the odor of drugs in the trunk. The Trooper opened the trunk where he found, among other things, two white trash bags with multiple sealed packages of marijuana. The trial court granted Cox’s motion to suppress the evidence, finding that it is “unreasonable for an officer to rely on the alert from a canine trained to detect any amount of marijuana, including legal amounts.” The trial court concluded that, based on the remaining factors to be considered, the Trooper did not have probable cause to search the trank. The People now bring this interlocutory appeal pursuant to section 16-12-102(2), C.R.S. (2016), and C.A.R. 4.1.
¶2 We now reverse and hold that Trooper Ynostroza had probable cause under the totality of the circumstances. Importantly, the trial court issued its order before we issued our opinion in People v. Zuniga, 2016 CO 52, 372 P.3d 1052, where we said that although Amendment 64 of the Colorado Constitution allows possession of small amounts of marijuana,
a substantial number of other marijuana-related activities remain unlawful under Colorado law. Given that state of affairs, the odor of marijuana is still suggestive of criminal activity. Hence, we hold that the odor of marijuana is relevant to the totality of the circumstances test and can contribute to a probable cause determination.
¶ 23, 372 P.3d at 1059. Under Zuniga, then, the trial court erred in disregarding the canine alert as part of the totality of circumstances.
¶3 Considering the canine alert as part of the totality of the circumstances, coupled with the fact that Cox had two cell phones on the car seat, exhibited unusual nervousness, and gave an inconsistent explanation regarding his travels, we hold there was probable cause to search the trank of Cox’s vehicle. We therefore reverse the trial court’s order suppressing the evidence found during the search and remand for further proceedings.
I,
¶4 Trooper Ynostroza testified1 that on the afternoon of January 5, 2016, he observed a lone vehicle driven by Cox traveling in the left lane on Interstate 76. The Trooper did not observe Cox pass any other vehicles or notice any obstructions that would require him to be in the passing lane, yet Cox remained in the left lane for the two miles that Trooper Ynostroza followed him. Because he believed Colorado law prohibits traveling in the left lane under such circumstances, the Trooper stopped Cox.
¶5 Cox provided Trooper Ynostroza with his driver’s license and rental car agreement. *511The Trooper called Cox’s information into dispatch and quickly received confirmation that his license was clear and valid. The Trooper noticed that Cox was unusually nervous; he based this conclusion on the fact that Cox had beads of sweat on his face, was stuttering, and was continuously licking his lips. Trooper Ynostroza testified that this was unusual and “not consistent with, the average or the normal consistent violator that we stop day in and day out.” He also saw two cell phones on the passenger seat. According to the Trooper, the presence of two cell phones and his other observations “led to the possibility that ... [Cox] could be trafficking illegal contraband.”
¶6 Trooper Ynostroza asked Cox to exit the car and come to the rear of the vehicle. Outside the ear, Cox told the Trooper that he had rented the car in Sunnydale, California, on Christmas Day, which was eleven days earlier, and had driven “straight through” on his way to Bellevue, Nebraska. The Trooper was familiar with the drive from California to Nebraska and believed that Cox’s explanation of his travel plans left eight days of driving unaccounted for. The Trooper examined the rental car agreement and noticed that the ear was four days overdue. Cox said that he would call the company, and that it had his credit card information on file. Trooper Ynostroza asked dispatch to contact the rental company. '
¶7 While waiting for information from the company, the Trooper asked Cox if he would mind opening the trunk, and Cox refused but acknowledged that the items in the trunk belonged to him. Over Cox’s objection, Trooper Ynostroza had his canine unit, Lobo, conduct a free air sniff. Lobo is trained to alert to the odor of marijuana, methamphetamine, heroin, and cocaine, but the Trooper testified that Lobo’s signal is the same regardless of the substance or quantity of the substance.
¶8 Lobo alerted on the trunk, and Trooper Ynostroza opened it, where, among other things, he found two white trash bags with multiple sealed packages of marijuana. Soon thereafter, dispatch reported back that the vehicle was due to the rental company but that Cox could extend the agreement.
¶9 Cox was charged with possession with intent to manufacture or distribute marijuana or marijuana concentrate, distribution of marijuana or marijuana concentrate, and improper usage of a passing lane. Cox asked the trial court to suppress the evidence obtained during the search of the vehicle’s trunk because Trooper Ynostroza did not have probable cause to support the search. The trial court agreed and granted his motion. According to the trial court, it was error for the Trooper to rely upon the canine alert because the canine would alert to both legal and illegal amounts of marijuana. The court continued, “It stands to reason that possession of a legal substance cannot form the basis of finding probable cause to search for contraband.” (Citing, inter alia, Commonwealth v. Overmyer, 469 Mass. 16,11 N.E.3d 1054, 1058 (2014)). The trial court concluded that the remaining factors — the fact that Cox gave inconsistent information regarding his travel plans, had two cell phones on the passenger seat, and exhibited unusual nervousness — did not amount to probable cause.2
¶10 The People filed this interlocutory appeal pursuant to section 16-12-102(2) and C.A.R. 4.1.3
II.
Till The People argue that the trial court erred by concluding that Trooper Ynos-troza did not have probable cause to search *512the trunk of the vehicle and suppressing the fruits of that search. We agree. Whether probable cause exists is a mixed question of law and fact. Zuniga, ¶ 13, 372 P.3d at 1056 (citing People v. Coates, 266 P.3d 397, 400 (Colo. 2011)). “When reviewing a trial court’s suppression order, we give deference to the trial court’s findings of fact but review its application of law denovo.” Id. (quoting People v. Vaughn, 2014 CO 71, ¶ 9, 334 P.3d 226, 229).
¶12 The United ’States Constitution and ' Colorado Constitution guarantee the right of the people to' be free from “unreasonable searches and seizures.” U.S. Const, amend. IV, XIV; Colo. Const, art. II, § 7. To satisfy the reasonableness requirement, law enforcement officials must obtain a warrant prior to a search, unless it falls within an exception. Zuniga, ¶ 14, 372 P.3d at 1056 (citing Mendez v. People, 986 P.2d 275, 279 (Colo. 1999)). One such exception applies to automobiles: law enforcement officials may search an automobile without a warrant “if they have probable cause to believe that the automobile contains evidence of a crime.” Id. (quoting People v. Hill, 929 P.2d 735, 739 (Colo. 1996)).
¶⅛ A law enforcement official has probable cause to conduct a search “when the facts available to the officer would warrant a person of reasonable caution in the belief that contraband or evidence of a crime is present.” Id. at ¶ 16, 372 P.3d at 1067 (alterations omitted) (quoting Florida v. Harris, 568 U.S. 237, 133 S.Ct. 1050, 1055, 185 L.Ed.2d 61 (2013)). Probable cause does not require certainty or even that it be more likely than not that a search will reveal evidence. People v. Swietlicki, 2015 CO 67, ¶ 32, 361 P.3d 411, 417. Rather, probable cause is a “nontechnical standard,” id, and a “commonsense concept,” Zuniga, ¶ 16, 372 P.3d at 1057 (citing Mendez, 986 P.2d at 280).
¶14 The probable cause determination requires a court to consider the “totality of the circumstances” to determine whether a “fair probability exists that a search of a particular place will reveal contraband or evidence of-a crime.” Id (quoting Mendez, 986 P.2d at 280). The standard requires the court to do more than consider all of the individual circumstances of a case in isolation from the others. Rather, a court must consider the “[fjacts in combination.” People v. Schall, 59 P.3d 848, 852 (Colo. 2002); see Maryland v. Pringle, 540 U.S. 366, 372 n.2, 124 S.Ct. 795, 157 L.Ed.2d 769 (2003) (“The court’s consideration of the money in isolation, rather-than as a factor in the totality of the circumstances, is mistaken in light of our precedents.”). The possibility that an innocent explanation may underlie a particular circumstance “may add a level of ambiguity to a fact’s probative value in a probable, cause determination, but it does not destroy the fact’s usefulness outright and require it to be disregarded.” Zuniga, ¶ 20, 372 P.3d at 1058.
¶15 We conclude that under the totality of the circumstances,, Trooper Ynostroza had probable cause to search the vehicle’s trunk. Four factors, in combination, support this conclusion.
¶16 First, Lobo the canine alerted on the trunk. The trial court dismissed this factor, concluding that it is “unreasonable for an officer to rely on the alert from a canine trained to detect any amount -of marijuana, including legal amounts.” The. court continued,. “It stands to reason that possession of a legal substance cannot form the basis of finding probable cause to search for contraband.” (Citing, inter alia, Overmyer, 11 N.E.3d at 1058).
¶17 Importantly, the trial court adopted this reasoning before. we issued Zuniga,4 where we addressed a similar suppression order that cited to Overmyer and reasoned that because the canine alerted to both legal and illegal amounts of marijuana, the alert had to be disregarded. Id. at ¶ 19, 372 P.3d at 1057-58. In Zuniga, however, we “dis-agree[d] with this reasoning.” Id. at ¶ 20, 372 P.3d at 1058. We observed that our precedent “is consistent with the principle that, while á possible innocent explanation may impact the weight given to a particular fact *513in a probable cause determination, it does not wholly eliminate the fact’s worth and require it to be disregarded.” Id. at ¶ 23, 372 P.3d at 1059. “Applying that principle to the trial court’s order,” we said that
while Amendment 64 [of the Colorado Constitution] allows possession of one ounce or less of marijuana, a substantial number of other marijuana-related activities remain unlawful under Colorado law. Given that state of affairs,-the odor of marijuana is still suggestive of criminal activity. Hence, we hold that the odor of marijuana is relevant to the totality of the circumstances test and can contribute to a probable cause determination.
Id. As in Zuniga, we conclude that, contrary to the trial court’s approach, the canine alert in this case, “suggested that illegal drugs were present in the vehicle” and that such an alert is a factor that should be considered as part of the totality of circumstances. Id. at ¶ 29, 372 P.3d at 1060.
¶18 Another factor weighing in the probable cause determination is that Trooper Ynostroza noticed that Cox was unusually nervous. We have recognized that it is natural for drivers to be nervous when they are stopped by a law enforcement officer. Id. at ¶ 27,372 P.3d at 1059. Here, however, Trooper Ynostroza did not merely notice that Cox was nervous; rather, ‘he was “unusually nervous,” and the Trooper testified that his nervousness was “not consistent with the average or the normal consistent violator that we stop -day in and day out.” The Trooper based this on his observations that Cox “had beads of sweat on his nose, he stuttered when speaking, and he continuously licked his lips.” As in Zuniga, we conclude that this unusual nervousness “leads to a reasonable inference that illegal activity was ongoing during the traffic stop.” Id., 372 P.3d at 1060.
¶19 Third, Trooper Ynostroza observed an inconsistency in Cox’s account of his travels. Cox told the Trooper that he had driven “straight through” from Sunnydale, California, to Bellevue, Nebraska, though Cox had rented his vehicle in Sunnydale eleven days before. Trooper Ynostroza was familiar with the drive from California to Nebraska and believed that Cox’s explanation left eight days of driving unaccounted for. Such inconsistencies in a person’s account of where he or she has been traveling can give rise to probable cause. See United States v. Edwards, 632 F.3d 633, 640 (10th Cir. 2001) (finding probable cause supported warrant-less arrest when, among other things, defendant “offered only implausible, inconsistent explanations of how he came into possession of money); United States v. Garcia, 179 F.3d 265, 269-70 (5th Cir. 1999) (finding probable cause existed when, among other things, “the defendants, responded to the agents’ questions with obviously false and inconsistent explanations”); People v. Omwanda, 2014 COA 128, ¶ 24, 338 P.3d 1145, 1149 (finding probable cause existed when, among other things, defendant gave inconsistent and conflicting explanations of recent whereabouts and reasons for being in Colorado).
¶20 The trial court noted that Cox’s claim that he drove “straight through” from Sun-nydale to Bellevue, and the fact that he rented the vehicle eleven days earlier, are “potentially inconsistent and potentially consistent.” The court continued that it did “find it odd that a person would rent a car on Christmas Day, then remain in their hometown for eight or nine days with a rental car, before departing to drive ‘straight through’ to their final destination.” But, the trial court found this factor to be “mitigated” based on the fact that the Trooper did not ask follow up questions to determine whether Cox could clear up any inconsistency. We are aware of no requirement that an officer ask clarifying questions regarding a person’s inconsistent explanation of his or her travel. Instead, we simply observe that such inconsistencies may give rise to “a-reasonable inference that [the defendant was] attempting to conceal illegal conduct from the Trooper.” Zuniga, ¶ 26, 372 P.3d at 1059 (considering the two men’s “remarkably disparate accounts” of their travels in Colorado in the totality of the circumstances).
¶21 Finally, Trooper Ynostroza saw two cell phones in the vehicle, which he testified is common among drug traffickers. Courts have recognized the connection between multiple cell phones and the possibility of drug trafficking. See, e.g., United States v. Green*514wood, 594 Fed.Appx. 486, 489 (10th Cir. 2014) (stating that multiple cellphones are typical of drug distributors); United States v. Guerrero-Sanchez, 412 Fed.Appx. 133, 139-40 (10th Cir. 2011) (finding that possession of two cell phones, among other factors, although all innocent in isolation, together create reasonable articulable suspicion of illegal conduct). But the trial court offered up two innocent explanations for the presence of two cell phones in the car — that someone else left the second phone, or that Cox had a work and personal cell phone — and faulted the Trooper for not following up with Cox so that he could supply such a “plausible explanation.” Again, we are aware of no requirement that an officer ask clarifying questions regarding the presence of two cell phones. Additionally, as with the canine alert, we note that the possibility of an innocent explanation “does not destroy the fact’s usefulness outright and require it to be disregarded.” Zuniga, ¶ 20, 372 P.3d at 1058. Here, the trial court erred in finding that the presence of two cell phones did not constitute a “suspicious fact[ ].”
¶22 Considering these facts together, there was a fair probability that searching the trunk would reveal contraband or evidence of a crime; this is all that probable cause requires. See Harris, 133 S.Ct. at 1055 (“A police officer has probable cause to conduct a search when the facts available to him would warrant a person of reasonable caution in the belief that contraband or evidence of a crime is present.... All we have required is the kind of fair probability on which reasonable and prudent people, not legal technicians, act.” (Alterations omitted)). Accordingly, we reverse the trial court’s conclusion that the search of the trunk was not supported by probable cause.5
III.
¶23 Because Trooper Ynostroza had probable cause, the trial court erred in suppressing the evidence found during the search. Therefore, we reverse the trial court’s order suppressing evidence obtained from the search and remand for further proceedings.
JUSTICE HOOD dissents, and JUSTICE GABRIEL joins in the dissent.. The following facts come from the trial court’s order or the transcript of the suppression hear-tag.
. Cox also argued that the initial basis for the stop was unlawful and that the scope of the stop was unlawfully extended twice. However, the trial court disagreed, finding that the initial basis for the stop was lawful and that extending the stop was justified. Cox again raises these issues in this appeal, in addition to opposing the People on the probable cause issue. However, we do not consider these other issues raised by Cox because a defendant cannot appeal a decision in favor of the prosecution under C.A.R. 4.1. People v. Zuni-ga, 2016 CO 52, ¶ 11 n.3, 372 P.3d 1052, 1056 n.3 (citing People v, Gothard, 185 P.3d 180, 183 (Colo. 2008)).
. The People certified that this appeal was not taken for the purposes of delay and that the evidence suppressed is a substantial part of the proof in the People’s case. See C.A.R. 4.1(a).
. The trial court issued its suppression order in this case on May 31, 2016. We issued Zuniga on June 27, 2016.
. As in Zuniga, because we conclude that probable cause was established by the totality of the circumstances, we need not consider whether the dog alert alone would establish probable cause in this case. Zuniga, ¶ 30 n.6, 372 P.3d at 1060 n.6.