San Antonio police working to gather more leads in a murder investigation after one person was shot to death on the west side.

It happened around 4 a.m. in the 2000 block of Delgado Street, but officers weren't notified until about 3 p.m.

When they arrived, they found the victim's body in a bathtub in a separate structure behind the home -- but they believe the victim's body was moved there.

Police say the victim is a white male in his early 20s. They believe he lived in the house with his girlfriend and her brother.

Investigators say all three were inside the home when the shooting occurred.

According to police, the victim's mother showed up at the home to look for her son because she hadn't heard from him since last night.

Police believe that's when victim's girlfriend called 911.

Officers then took the girlfriend's brother into custody after a short search.

Police say they're also still trying to locate the murder weapon.

As for the brother of the victim's girlfriend, police are only treating him as a person of interest.