A Wauwatosa police officer ran a check on the license plate of a 2016 Dodge Caravan that was parked at Mayfair mall shortly before 5 p.m. on May 7, a Sunday, and found that it had been reported by Milwaukee police as having been stolen.

Another officer using a lockout tool then opened the van to find the vehicle identification number and learned that the van itself had also been reported by Milwaukee police as stolen.

The officers disabled the vehicle and found a loaded Glock Model 42 pistol under the driver's seat. A strong odor of marijuana was evident. Then they waited until 21-year-old north side Milwaukee resident Amari S. Hampton, with two flip phones hanging from a lanyard around his neck, arrived with a woman.

That's all according to a criminal complaint filed last week in Milwaukee County Circuit Court charging Hampton with four felonies involving drugs, the gun and vehicle theft.

RELATED: Overdose deaths rise as carfentanil emerges.

Officers took Hampton and the woman into custody after he got inside the Caravan and tried to start it. Inside the vehicle, the complaint says, were 29 grams of fentanyl, nearly 24 grams of heroin, some marijuana and drug paraphernalia.

Hampton told officers he didn't know the van was stolen and told the woman with him not to tell the officers anything.

Fentanyl is a prescription opioid painkiller that is similar to morphine but 50 to 100 times more potent. It can also be 50 times more powerful than heroin.

In 2016, 97 drug overdose deaths in Milwaukee County involved fentanyl, compared with 16 in 2011, according to the county medical examiner.