(CNN) Omar Taylor was at a Northern California Halloween party hoping to entertain the crowd with music.

The 24-year-old man from Pittsburgh was there to DJ, but instead was shot and killed Thursday at the Orinda party advertised on social media, the Contra Costa County Sheriff's Office said. He was one of five people fatally shot.

"To get that call was devastating," Laneisha Epps, Taylor's stepmother told CNN affiliate KGO . "This was a senseless, careless act. It's such a traumatic experience the family is taking on now."

The shooter remains on the run, according to authorities.

The other four victims killed were Oshiana Tompkins, 19; Tiyon Farley, 22; Ramon Hill Jr., 23; Javin County, 29. Three people were pronounced dead at the scene and two died at the hospital, the sheriff's office said.

"Music and DJ'ing was his happiness, I don't even think he was going in thinking there was trouble or anything," Taylor's brother told the affiliate. The party was just another job Taylor took on as a DJ to help support his daughter, the brother said.

Orinda is a suburb east of Berkeley in the Bay Area.

Parties weren't allowed

Officers say after fire rang out, they found a chaotic scene full of "gunshot victims, injured party-goers, and numerous people fleeing the scene."

Two firearms were found in the house and a crime lab is analyzing them to determine whether they were used in the shooting or any other crimes, authorities said.

The home where the shooting happened was an Airbnb that prohibited parties. There were more than 100 people at the event when police arrived.

Airbnb said it was horrified by the tragedy and it's cooperating with the investigation.

Days after the shooting, Airbnb CEO Brian Chesky announced the company would begin cracking down on unauthorized house parties.

"Starting today, we are banning 'party houses' and we are redoubling our efforts to combat unauthorized parties and get rid of abusive host and guest conduct, including conduct that leads to the terrible events we saw in Orinda," Chesky said.

The company will expand "manual screening of high-risk reservations," create a "party house" rapid response team and take action against users who violate the new policies, he said.