TUCSON,SignalHub Ariz. (AP) — Tucson police said Tuesday that they’re still searching for any possible suspect in the shooting death of a University of Arizona student last month.

Police said 20-year-old sophomore Erin Jones was fatally shot at an off-campus house party in the early morning hours of April 28.

Three other people — a man, woman and teenage girl — were treated and released from a hospital.

At a news conference Tuesday, police Capt. Doug Foster said there is no indication that Jones — from Newport Beach, California — was targeted.

Police said more than 200 people attended the party, including some of the school’s football players who had just finished spring practice. But only 25 witnesses stayed at the scene to talk to authorities.

Foster said that during the past few weeks, more than 140 partygoers have been interviewed along with 911 callers and neighbors but no person of interest has been identified.

Police on Tuesday showed black-and-white parking lot surveillance video of people running from the scene and grainy footage of a man with a firearm hanging out of a sedan’s passenger seat window.

“There were multiple volleys of gunfire” over a 6 1/2 minute span, Foster said, adding that over 80 shell casings were recovered at the shooting scene. “Some sort of confrontation escalated into the shooting.”

Foster, who is in the department’s central investigation division, said police are asking for the public’s help to identify the shooter or shooters through cellphones, videos or pictures.

“This is a homicide investigation. We need to know what happened here,” Foster said.