CASA GRANDE, Ariz. -- A man made off with a police vehicle and 75 pounds of marijuana they had used for bait in a drug sting, the Pinal County Sheriff's Office said.

Deputies from the county's drug task force set up the deal to close out a month-long investigation in Casa Grande.

Court records show undercover deputies agreed to trade a Hummer vehicle for the marijuana they possessed from a prior drug seizure.

But the deal went sour on Wednesday at the Casa Grande Promenade Mall parking lot off Interstate 10 when five men showed up in the Hummer and a pickup. One got into a sedan with the pot and drove away before a SWAT team could close in. The other four were arrested.

Deputies said they recovered the car in Eloy, minus the marijuana and some surveillance equipment. No weapons were missing, they said.

Pinal County chief deputy Jeff Kirkham said such failed stings are rare and played down the effect of losing the marijuana.