A security guard working at the downtown Greyhound bus station was shot and killed Thursday afternoon, police said.
The shooting occurred about 3:15 p.m. after the guard searched a man's bag and discovered a weapon, said San Antonio Police Department spokesman Sgt. Gabe Trevino.
A suspect was arrested.
The gunman, who police believe was in his 20s, had been at the bus station at 500 N. St. Mary's St. for several hours and had befriended a homeless man, who took him somewhere to buy marijuana, Trevino said.
When they returned to the bus station, the gunman showed his weapon to the homeless man, who then notified the guard about the gun, Trevino said.
The guard took the man into a customer service office and searched his bag.
When he found the gun, the guard placed it on the counter and picked up the phone to call his supervisor and the police, Trevino said.
The gunman stood, pushed the guard to the ground, grabbed the gun and shot the guard in the chest, Trevino said.
The guard, whose name was not immediately released, died at Brooke Army Medical Center.
The shooter fled on foot. Police apprehended a suspect on the streets about 30 minutes later.
John Castillo, a cab driver who saw the shooter fleeing while struggling to conceal his weapon in his waistband, said he chased the man across the street.
The guard was well-liked and courteous. "He was a good guy," said Jesus Garcia, who services buses at the station.
Rudy Morales works near the bus station and often spoke with the guard.
"He's a quiet guy, very nice," Morales said. "But now he's dead."