At about 5:30 p.m., a man called police to say his friend had been shot through both legs by an acquaintance near 1500 South and State Street, Salt Lake City Police Lt. Scott White said.

As police investigated, they began to suspect the shooter was holed up in a nearby Express-N-Go convenience store.

"An officer thought he saw lights go off and on, and thought, 'Hey, this guy is in here,'" White said. About 20 officers, including SWAT team members, settled in outside the store, trying to call the man assumed to be inside. An apartment is behind the store.

They were also talking to the 43-year-old suspect's girlfriend, who is connected with the store through ownership or employment. She initially promised to let police inside, White said, but never came.

Around 7:30 a.m., more than 11 hours after the standoff began, officers obtained a search warrant and stormed inside.

"He wasn't in there," he said. "No one was in there."

The suspect is described as a Vietnamese man, approximately 5 feet 6 inches tall, weighing 135 pounds. The victim, who is in his mid-30s, is also Vietnamese, White said. He was taken to a hospital in stable condition.

Police do not know what caused the shooting, although the two men appear to have known each other, White said. It does not appear to be gang related, he said.