Later Tuesday, law enforcement sources confirmed that the gun used in the shooting belonged to a federal agent, but no details were available about how the suspect may have obtained the weapon, or whether it had been lost or stolen.

In a weekend interview with KGO-TV, which on Tuesday first reported the gun’s connection to the federal agent, Juan Francisco Lopez-Sanchez said he had found the weapon wrapped in a T-shirt on the ground near a bench, and that it had accidentally fired when he touched it.

But he also said he had taken strong sleeping pills and his memory was murky.

The district attorney’s office declined to comment on the gun.