A 19-year-old man was shot early Monday morning after police say he and another man, 18-year-old William Beasley, attempted to rob a man and woman in the parking lot of Auburn Plaza. Credit: CBS 13 | WGME

A 19-year-old man was shot early Monday morning after police say he and another man attempted to rob two people in an Auburn parking lot.

Credit: Courtesy of the Auburn Police Department via CBS 13

William Beasley, 18, of Auburn was charged with robbery, while the 19-year-old, who has not been identified, was listed in critical condition at Central Maine Medical Center in Lewiston, according to the Auburn Police Department. Police said more charges are expected.

A man and woman were talking after work in the parking lot of the Auburn Plaza on Center Street about 12:20 a.m. when two men approached them, brandished a firearm that was later determined to be a BB gun modified to look like a revolver and demanded their wallets and cellphones, Auburn police said Monday afternoon.

The man told the two suspects he needed to get those items from his vehicle. But as he went to his vehicle, he retrieved his 9 mm handgun and fired several shots at the suspects, according to Auburn police.

One shot struck the 19-year-old in the chest, Auburn police said. The other suspect, Beasley, attempted to provide first aid. When police arrived, they continued to provide first aid until members of the Auburn Fire Department arrived and took the 19-year-old to the Lewiston hospital.

Beasley was being held on $25,000 bail.

The Maine State Police are assisting Auburn police with the investigation.