Police said it all started when the Texas Lawman Security guard approached a resident at the Woodhill Apartments in the 4900 block of Woodstone, and the pair began arguing.
The San Antonio Police Department said the argument started when the security guard asked the man to leave the complex's pool that was closed and discard a beer he was drinking.
When the man did not comply, the guard attempted to detain him.
However, police said the man knocked the guard's head on the ground, hitting it on the concrete.
The man also threatened to kill the guard, according to police.
At some point in the scuffle, the security officer pulled out a gun and shot the resident.
Police said the security guard shot the man in the abdomen, but his injury is not life-threatening