The incident happened last week.
According to the Upland Police Department, officers received a call about two men in a Mercedes-Benz without license plates who were breaking into mailboxes.
Officers located the vehicle at a gas station at the intersection of Foothill Boulevard and Benson Avenue.
Police said that during a search of the vehicle, officers found items like stolen mail, burglary tools and drug paraphernalia.
"We also went back to the gas station trash and found more mail," read a post on X. "Aside from the items above, there was a lot of merchandise from one of our retail stores that had a receipt."
Police said the suspects used a stolen credit card to buy more than $1,000 worth of merchandise. The suspects were arrested and booked for commercial burglary, felony identity theft, mail theft and drug related charges.
The vehicle was also impounded.
The incident remains under investigation.