The incident began about 4:10 p.m. Saturday at the King Arthur Estates Mobile Home Park in the 100 block of Sir Bedivere Drive, according to Riverside police Officer Ryan Railsback.
A woman was shot inside a home at the mobile park. She was taken to a local hospital where she later died.
Three children were safely removed from the home, but the suspect barricaded himself inside.
After an hours-long standoff, SWAT officers entered the home and found the man dead.
Investigators are working to determine what led up to the deadly shooting.
City News Service contributed to this report.