JUSTICE APPLETON delivered the opinion of the court:

The State charged defendant, James A. Schmitt, with variousdrug offenses, but the trial court granted in part his motion toquash his arrest and suppress the evidence against him. Having fileda certificate of impairment, the State appeals, arguing the policehad probable cause to stop and search the truck Schmitt was driving. Because we agree with the State, we reverse the quashing of Schmitt'sarrest and the suppression of evidence, and we remand this case forfurther proceedings.

Early in the afternoon on August 13, 2002, Mike Cottrell, aloss-prevention manager at Wal-Mart in Decatur, called the MaconCounty sheriff's department and reported that a blond, curly-hairedman, clad in a gray T-shirt, had just bought two boxes ofpseudoephedrine. The man was later identified as Chad A. Hinthorne. When the police arrived, Hinthorne had already departed. He had mettwo other men outside the store, and the three headed south on StateHighway No. 51 in a red Ford pickup truck with black ladder racks andlicense-plate number 1454 KR. The two other men were later identified as Schmitt and Gary Garland. Schmitt was the driver, althoughthe truck was registered to Hinthorne at an address in El Paso, inWoodford County, some 67 miles north of Decatur.

Soon afterward, a police officer spotted the truck on StateHighway No. 48 and followed it to a business called "The Shop," whichspecialized in the sale of drug paraphernalia. All three occupantsof the truck went into The Shop, and when they reemerged, one of themput something into the truck's toolbox, apparently a purchase.

The truck then went to Fairview Plaza Shopping Center, andthe three got out and entered Ma Belle's Family Restaurant. Shortlyafterward, Hinthorne came out of the restaurant and walked to aDollar General store nearby. A police officer followed him into thestore and watched him buy two more boxes of pseudoephedrine. Aftercarrying the two boxes to the truck and stashing them in the toolbox,Hinthorne returned to the restaurant.

From the restaurant, the trio went north on State HighwayNo. 48 (with an undercover police officer following) and stopped atanother Dollar General store. This time Schmitt entered the store,and a police officer followed him and watched him buy two boxes ofpseudoephedrine.

Thus, within two hours, Hinthorne and Schmitt had bought atotal of six boxes of pseudoephedrine. Each box had 20 pills. Ifone continuously took the maximum dosage--2 pills every 6 hours--onebox would have been roughly a 2-1/2-day supply for one person.

Because of the multiple purchases of pseudoephedrine, thepolice pulled the pickup truck over and questioned Hinthorne,Schmitt, and Garland on the side of the highway.

At the hearing on the motion to suppress, the prosecutorasked one of the police officers, James Root:

"A. In fact, did you later run, did you runa check on Mr. Hinthorne, a warrants, Mr.Garland a warrants check?

Q. Yes. Mr. Garland was wanted."

A search of the truck revealed not only the six boxes ofpseudoephedrine but also four lithium batteries in the glove box anda container of acetone behind the driver's seat. The police had nowarrant, and neither the owner of the truck, Hinthorne, nor thedriver, Schmitt, had consented to the search.

Later, in an interview at the police station, Garlanddivulged that methamphetamine was hidden under the ashtray of thetruck. After obtaining a search warrant, the police searched thetruck a second time and found the methamphetamine under the ashtray. They also searched Hinthorne's house in El Paso and found over 1,000grams of methamphetamine "in various stages of the cooking process."

The trial court held as follows: (1) the police had "anarticulable suspicion adequate to justify the investigatory stop ofthe truck"; (2) the police "did not have probable cause to arrest thevehicle's occupants prior to locating the pills, batteries[,] andacetone during the initial search of the truck"; (3) the police "didnot have permission to search the truck from anyone with authority";(4) the police "did not have probable cause to conduct the initialsearch of the truck"; and (5) insufficient evidence was "presentedfor the court to determine whether the subsequent searches of thetruck and [Hinthorne's] home were proper." Therefore, the courtquashed Schmitt's arrest; suppressed the pseudoephedrine, lithiumbatteries, and acetone found in the truck; and also suppressedSchmitt's postarrest statements. The court declined, however, tosuppress any statements Schmitt made "during the initialinvestigation stage of the stop."

This appeal followed.

We will give great deference to the trial court's factualfindings, reversing them only if they are against the manifest weightof the evidence (People v. Sorenson, 196 Ill. 2d 425, 431, 752 N.E.2d1078, 1083 (2001))--that is, only if all reasonable and unbiasedpersons would agree the evidence clearly points to the oppositefinding (People v. Miles, 343 Ill. App. 3d 1026, 1030, 798 N.E.2d1279, 1283 (2003)). We will review de novo the ultimate question ofwhether the seizure and search were constitutional. Sorenson, 196Ill. 2d at 431, 752 N.E.2d at 1083.

The trial court held the police had a reasonable,articulable suspicion of criminal activity and, therefore, ajustification for a brief investigatory stop. See Illinois v.Wardlow, 528 U.S. 119, 123, 145 L. Ed. 2d 570, 576, 120 S. Ct. 673,675 (2000). Notwithstanding their right to stop the truck andquestion the occupants about the pseudoephedrine, the police couldnot legally search the truck unless they had probable cause tobelieve it contained contraband (see People v. Penny, 188 Ill. App.3d 499, 502, 544 N.E.2d 1015, 1016 (1989); People v. Clark, 92 Ill.2d 96, 99, 440 N.E.2d 869, 871 (1982)) or evidence of a crime (seePeople v. James, 163 Ill. 2d 302, 312, 645 N.E.2d 195, 200 (1994)). Probable cause is a more rigorous standard than reasonable,articulable suspicion. United States v. Sokolow, 490 U.S. 1, 7, 104L. Ed. 2d 1, 10, 109 S. Ct. 1581, 1585 (1989). The court held thepolice lacked probable cause.

The State invoked the inevitable-discovery rule. Underthat rule, "evidence that otherwise would be inadmissible may beadmitted if the prosecution can show that the evidence '"wouldinevitably have been discovered without reference to the police erroror misconduct."'" People v. Mitchell, 189 Ill. 2d 312, 342, 727N.E.2d 254, 272 (2000), quoting People v. Edwards, 144 Ill. 2d 108,142, 579 N.E.2d 336, 349 (1991), quoting Nix v. Williams, 467 U.S.431, 448, 81 L. Ed. 2d 377, 390, 104 S. Ct. 2501, 2511 (1984). TheState argues that even if, as the trial court held, the search of thepickup was unsupported by probable cause, the police would haveinevitably discovered the lithium batteries and acetone anywaybecause Garland was wanted on a warrant and upon lawfully arrestingthe occupant of a vehicle, the police may search the passengercompartment of that vehicle as well as containers within thepassenger compartment. See People v. Allibalogun, 312 Ill. App. 3d515, 519, 727 N.E.2d 633, 637 (2000).

Whether the police would have inevitably discovered thebatteries and acetone as a result of the outstanding warrant onGarland depends on (1) whether they would have inevitably performed awarrant check on Garland at the scene of the stop, considering thathe himself had bought no pseudoephedrine, and (2) whether, havinglearned of the warrant, they would have inevitably searched the truckas an incident of arresting Garland. As Root admitted on the stand,the police wanted all along to search the truck. They probably wouldnot have knowingly passed by a legal opportunity to so. Therefore,the answer to (2) is probably yes. The answer to (1), however, isuncertain. Clearly, the police did, at some point in time, perform awarrant check on Garland, but the record does not seem to reveal whenand why they did so. If they performed the warrant check on him onlybecause of their discovery of the batteries and acetone in the truck,the warrant check probably was not inevitable in the sense that theywould have performed it anyway.

In any event, the inevitability of the discovery of thebatteries and acetone was a question of fact. At the conclusion ofthe hearing on the motion to suppress, the prosecutor argued "thepolice could have searched the interior of that [truck] based on thefact that there was a warrant out for Mr. Garland." Although thetrial court never mentioned the inevitable-discovery rule in itsfactual findings, it apparently disagreed with the prosecutor'sargument, and we will defer to the trial court in that factualdetermination. See Sorenson, 196 Ill. 2d at 431, 752 N.E.2d at 1083.

A police officer has probable cause to search a vehicle ifthe totality of circumstances known to the officer at the time of thesearch, in light of the officer's law-enforcement experience, wouldjustify a reasonable person in believing the vehicle containedcontraband (People v. Smith, 95 Ill. 2d 412, 419, 447 N.E.2d 809,811-12 (1983)) or evidence of a crime (James, 163 Ill. 2d at 312, 645N.E.2d at 200).

Pseudoephedrine is derivative contraband if one possessesit to manufacture methamphetamine. 720 ILCS 570/401, 102(z-1) (West2002); see People v. Steskal, 55 Ill. 2d 157, 159, 302 N.E.2d 321,323 (1973) (defining "derivative contraband" as property "notinherently illegal" that is "used in an unlawful manner"); Black'sLaw Dictionary 318 (7th ed. 1999) (defining "derivative contraband"as "[p]roperty whose possession becomes unlawful when it is used incommitting an illegal act"). Given the totality of the circumstancesknown to them at the time of the search, in light of their experienceinvestigating the manufacture of methamphetamine, did the policereasonably believe the truck contained contraband?

The emphasis should fall on "the totality of thecircumstances," the complete picture. Any one feature of thepicture, by itself, might appear innocuous, but when a police officerstands back and regards the whole picture with a trained eye, he orshe might recognize probable criminal activity. As the namesuggests, "probable cause" requires only a "probability orsubstantial chance of criminal activity," not a certainty. Illinoisv. Gates, 462 U.S. 213, 244 n.13, 76 L. Ed. 2d 527, 552 n.13, 103 S.Ct. 2317, 2335 n.13 (1983). "By hypothesis, therefore, innocentbehavior frequently will provide the basis for a showing of probablecause." Gates, 426 U.S. at 244 n.13, 76 L. Ed. 2d at 552 n.13, 103S. Ct. at 2335 n.13. "In making a determination of probable cause[,]the relevant inquiry is not whether particular conduct is 'innocent'or 'guilty,' but the degree of suspicion that attaches to particulartypes of noncriminal acts." Gates, 462 U.S. at 244 n.13, 76 L. Ed.2d at 552 n.13, 103 S. Ct. at 2335 n.13.

Within a space of two hours, Hinthorne, 67 miles from home,bought two boxes of pseudoephedrine at Wal-Mart and two more boxes atDollar General. Except for a T-shirt that he bought at Wal-Mart, heapparently bought nothing else at those stores. Root observed: "Thefact that they [sic] are going in to buy just pseudoephedrine pillsat [Wal-mart] is a little significant. When I go shopping forpseudoephedrine pills, I buy two boxes of pseudoephedrine pills and ahundred dollars worth of groceries." Another occupant of the truck,Schmitt, bought two more boxes of pseudoephedrine at a separateDollar General store. Root testified that in his experience as amember of the Illinois State Police Drug Task Force, manufacturers ofmethamphetamine had a modus operandi: they made separate purchasesof pseudoephedrine at separate stores by separate buyers in anattempt to minimize suspicion while maximizing the total amount ofpseudoephedrine they could safely purchase. Further, if they livedin a small town, they made the purchases far away from home wherethey would likely not be recognized. That the three occupants of thetruck also visited a "head shop" tended to strengthen the inferencethat they were involved in illegal drugs.

Given the totality of the circumstances, a reasonableperson would conclude that Hinthorne and Schmitt bought thepseudoephedrine probably not for a legitimate purpose but for themanufacture of methamphetamine and there was a substantial chance thetruck contained contraband or evidence of the manufacture ofmethamphetamine. Postulating innocent explanations does notnecessarily defeat probable cause.

For the foregoing reasons, we reverse the quashing ofSchmitt's arrest and the suppression of evidence, and we remand thiscase for further proceedings not inconsistent with this order.

Reversed and remanded.

STEIGMANN and McCULLOUGH, JJ., concur.