"What we do know is that the two victims are deceased and they're victims of gunshot, and we're out interviewing a number of witnesses as well as family members to determine what occurred, who they may have had issues with or problems with," says LAPD Capt. Ivan Minsal.
The shooting happened right across the street from a church. At the time, mass had just finished.
A nearby resident, Isabel Presido, says she heard at least 10 shots coming from the courtyard.
She describes the moment as "shocking, very fast."
"In an instant, you're calm, and all of a sudden, you just hear blasting everywhere," she adds.
No one else in the complex was hurt, even though dozens of children were in the vicinity.
"There were a number of witnesses, and family members detectives are going through," says Minsal.
"It was a classic Sunday afternoon with nice weather, and people were out enjoying the day when this occurred," he adds.
Police say community workers have been working hard to keep crime down in this gang-infested area.
Neighbors say it's been a long time since something like this has happened here.
"We're trying to find something better so we can get out of here, because even though it's a good area, I can say that it's not a good place so my son can grow here," Predsido says.
Anyone with information is urged to call Foothill detectives at (818) 834-3115. Police said all tips will remain anonymous.