The incident began about 11:45 a.m. in the 9400 block of Tamarisk Avenue, according to the San Bernardino County Sheriff's Department. Deputies responded to a mobile home park over a call about a man with a gun.
Witnesses said the suspect pointed a gun at a neighbor for an unknown reason.
Sheriff's officials said the man was cooperative at first but then refused to come out of the home.
At about 7:45 p.m., Cindy Bachman of the sheriff's department said in a tweet that an officer-involved shooting occurred involving the barricaded suspect, adding that it's unknown if he was shot by deputies or if the injuries were self-inflicted.
The unidentified suspect was pronounced dead, officials said.
Details on what led to the officer-involved shooting were not immediately released as the sheriff's department continued its investigation.