Authorities said they visited that ranch-style house only once, in April, after a neighbour reported yelling and crashing sounds. Somewhere between 10 and 15 more were injured.
Carl Edgar, 24, of Tarzana said: "As far as I know, all of my friends are OK, safe".
The PBS NewsHour will update this story as it develops.
He added that Helus was a "hard-working, dedicated Sheriff's Sergeant".
Mowry-Housley found fame on the USA sitcom Sister, Sister alongside her twin Tia back in the 1990s. He was killed in a shootout with the gunman.
"He was a hero before and he remains a hero now", said Ventura County Sheriff Union President Scott Peterson, who went to the academy with Helus some 30 years ago.
"The companionship that I had with my son, the companionship that my son had with his brothers", Jason said, breaking into tears as he embraced his father-in-law and kept his arm wrapped around him.
"First thing I said was 'Please don't drink and drive.' Last thing I said was 'Son, I love you'".
The father-of-one is survived by his wife Karen and son Jordan.
"I started hearing these big pops".
Sarah Rose DeSon told ABC's "Good Morning America" that she saw the shooter draw his gun.
Neighbours said Thursday they would hear loud, aggressive fights between the two.
"This is not going to be easy for our family for a very long time", he said.
He then shot patrons who were attending the venue's country music night for college students, Dean said. She was the niece of actor and The Real host Tamera Mowry-Housley and her husband Adam Housley.
"Our hearts are broken", the couple said in a joint statement.
The suspect, who was armed with a.45-caliber handgun, was found deceased at the Borderline Bar and Grill, the scene of the shooting in the city of Thousand Oaks northwest of downtown Los Angeles.
Knapp said he has friends who haven't been accounted for.
"We have a faith in our God, in our Christ", Johnston said. "And we feel for the people involved, that it happened to". "You just don't expect it to happen in Thousand Oaks".
"(He) said to her, 'Hey I got to go handle a call.
"It's a horrific scene in there", Dean said at a news conference early Thursday in the parking lot of the Borderline Bar & Grill. "It's too frequent an occurrence and it hurts every time, but it's never hurt like this before". It is expected that students from both schools are in attendance on the night of the shooting.
"Oh, Cody, I love you, son", Coffman sobbed. She said she hid with a group of strangers and they were holding hands.
"There's not a better place for us to be", Bayless said. "We're in mourning as a community".
The university didn't cancel classes, but held an afternoon prayer service.
"He went in there to save people and paid the ultimate price", he said.
Pepperdine officials say they're offering support to students through the university's counseling center and chaplain's office.
Federal Bureau of Investigation officials were seen visiting a residence believed to be Long's in Newbury Park, California, which neighbors Thousand Oaks. Hours into the tragedy no one had been reunified with a loved one.
Telemachus Orafnos's mother confirmed his death to ABC7.
At least 13 people were killed, including the gunman. He was part of the infantry, responsible for hauling and shooting machine-guns.