The man was trying to pick fights inside the bar, challenging people to take him on.

He got no takers.

After some patrons tried to calm him down and convince him to leave the bar, they spotted a gun in his pocket and felt the body armor beneath his shirt. That’s when they filled in the bartender, who called police.

Officers arrived at the bar in the 3500 block of McKinley Avenue about 10:45 p.m. The man was standing outside when police arrived but took off running as they approached him.

Officers were about 15 feet behind the man when he turned into an alley, police spokeswoman Loretta Cool said.

“When they followed him, he was reaching into his waistband,” she said.

One of the officers fired a single round, which did not hit the man but startled him so much he dropped to the ground and complied with police orders.

He was arrested on suspicion of obstructing a police officer. The officer who fired his gun was placed on administrative leave while the incident is investigated, which is standard procedure after a police shooting.