Police accidents are sometimes reported with a remarkable lack of agency.  Here is the entire substance of the report:

“An officer is hospitalized after he shot himself in the leg while he was off-duty in west Houston, according to the Houston Police Department.  Authorities say his gun went off, and the officer was shot in the leg while in an apartment building near Upper Kirby.”

There is an ongoing investigation.

Source:

“Off-duty HPD Officer Injured After Gun Goes Off and Shoots Leg,” ABC 13 Eyewitness News (May 19, 2020).