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Wednesday, authorities, neighbors and family members are all wondering why this happened.
Three people were killed: a father and his two sons. Investigators think one of the three shot and killed the other two, then turned the gun on himself. A handgun was found inside the house.
"We are looking at this as a possible murder-suicide," said Jerry Franchville, Riverside County Sheriff's Dept. spokesman. "Currently we don't have anyone in custody and we are not actively looking for any suspects."
One neighbor said he heard a total of six gunshots. The shots came in pairs, each pair separated by about a minute.
Another neighbor was outside when one of the other family members came home and discovered what happened a couple of hours later.
"One of the guys went inside, and he was all scared," said neighbor Maria Esquiel. "He came running and he told his girlfriend, and his girlfriend started saying, 'Oh, my family, my family is all dead,' and I got the goosebumps. It was scary."
The youngest victim was 12 years old. Kids in the neighborhood say they played basketball and soccer with him.
"He was a nice kid, and he was just quiet a lot, just quiet," said neighbor Troy Stephens.
"It was always quiet [at the house]," said neighbor Davieonne Kelly. "The father never came outside. You wouldn't ever seem them too much."
Police are not saying who the shooter was, nor are they saying anything about why this might have happened.
"After having talked to some of the family members and some of the neighbors, there seemed to be a shock and a surprise to everybody here," said Franchville.
Just a few moments ago, a little girl walked up, took a piece of paper and posted it on the garage, a handwritten note that says "I'm sorry for your loss."
The victims have been identified as 62-year-old Alvaro Gonzalez, 27-year-old son James Gonzalez, and 12-year-old son Jordan Gonzalez.
Eyewitness News Reporter John Gregory contributed to this report.