A Billings Wal- Mart employee suspected of shooting a co-worker in the head during an argument has been released from custody while police investigate whether the shooting was self defense. Sgt. Jay Berry says 49-year-old Craig Schmidt was arrested Monday night after 32-year-old Daniel Lira hit him in the face during an argument at the store’s loading dock. Police say Schmidt fell backward after he was hit, then used a small handgun to shoot Lira in the head. Lira was treated at the hospital and released. Yel lowstone County At torney Dennis Paxinos told police that Schmidt should be released from custody under a law passed by the Montana Legislature last session. House Bill 228 may require the state to prove that the use of force was not justified when a shooter makes a self defense claim. Paxinos was among those testifying against HB228. Police have arrested a man susp e c t e d o f shooting a co-worker in the head at a Wal-Mart in Billings' West End neighborhood Monday night. Police Sgt. Jason Gartner said authorities arrested Schmidt at gunpoint on the loading dock of the Wal-Mart in Billing’s West End neighorhood at about 9:30 p.m. and found a semiautomatic pistol nearby. Police found the victim inside the loading dock area with a gunshot wound to the head. Gartner said the Lira, who worked with Schmidt at the Wal- Mart, was conscious and holding a rag over his face when authorities arrived. The victim was taken to St. Vincent Healthcare, but his condition was not immediately known. "These guys knew each other," Gartner said. "They had words and a shot was fired." Kelsey Borsious and Tera Segura said they were shopping for cat toys when several police officers came running into the store. "There were seven or eight of them," Segura said. "It was like a SWAT team of cops." The store was evacuated, and hundreds of people were seen milling around the parking lot after the shooting.