Investigators said Mario Hernandez entered the home in the 500 block of Harvard Boulevard and shot his ex-girlfriend and three of her roommates. They said Hernandez set the house on fire before turning the gun on himself.
One of those roommates, Laurel Choy, described what happened to a friend from her hospital bed.
"The shooter entered her home, and it would not surprise me if Laurel had her door unlocked, because she's just that kind of a person," said Choy's friend, Katie McCall. "She was home, and that he walked straight into her bedroom and began to spray her with fluid that smelled like lighter fluid. Before she could even respond, he began to shoot her."
McCall said Choy is a close friend who gave her and her two children a place to stay when they were in a difficult situation.
McCall is organizing a fundraiser for Choy and the two other wounded roommates. All three are expected to survive.
Choy was scheduled to undergo surgery.
The blaze claimed nearly all of their possessions. A website has been set up to help the victims with donations.
Anyone with information regarding this incident should contact the Los Angeles Police Department at (877) LAPD-24-7.