DETROIT – A would-be robber was shot after trying to mug an off-duty Detroit police officer who happened to be in the wrong place at the wrong time.

The incident happened near the corner of Carpenter and Moran streets on the Detroit-Hamtramck border before 1 p.m. Saturday.

The off-duty officer was standing outside talking on his phone when he was approached by a young black man. A witness told Local 4 that's when he saw the would-be robber pull out the gun.

The off-duty officer ran back into the pharmacy, closing two glass doors behind him. Meanwhile, the robber picked up his gun and started following the man, trying to get inside.

At that point the off-duty officer had his gun ready.

A nearby business owner came out of his store moments after the shooting and said the suspect was shot in the head.

The witness said the officer kept his foot on the suspect's hand as they waited for police to arrive. The witness said even after being shot the suspect was threatening the officer.

Witnesses told Local 4 they were told by police that the suspect is 18 years old. Police are not releasing his name. The suspect was at Detroit Receiving Hospital with serious injuries.