DETROIT — A man fatally shot another customer inside a Detroit gas station and wounded two more after the clerk locked the door in a dispute over a small purchase, authorities said Wednesday.

Details emerged as prosecutors charged Samuel McCray, 27, with murder and attempted murder. He was denied bond during a court appearance.

The shooting occurred after 3 a.m. Saturday. McCray tried to leave the gas station with items worth less than $4 after an electronic purchase was rejected, but the clerk locked the door, the prosecutor’s office said.

McCray threatened to shoot everyone inside the gas station unless the door was unlocked, according to witness David Langston.

Langston told WJBK-TV that he begged McCray: ”‘Please, man, don’t shoot us. We don’t got nothing to do with this.’ ... And he started shooting.”

Langston, 37, was wounded but his best friend, Gregory Kelly, 37, was killed. A 60-year-old man was also wounded.

“After the men were shot, the clerk unlocked the door to the store, and McCray fled from the scene,” the prosecutor’s office said.

McCray was returned to jail after appearing in court Wednesday. He asked for a court-appointed attorney.

Prosecutor Kym Worthy had planned to hold a news conference but canceled it and said the investigation was ongoing.

Kelly “had plenty of friends,” his mother, Marilyn Fortner, said. “He just did not deserve a death like that.”