Police were looking for witnesses on Wednesday after a triple-shooting near a high school campus in the West Los Angeles area left one person dead, police said.

Gunfire erupted at 9:03 a.m., police said. Officials found victims in the 8900 block of West Helms Place and in the 3100 block of South Helms Place, said Katherine Main of the LA Fire Department.

Police described a man wearing dark clothing, "carrying a gun and chasing victims through the neighborhood." Aerial video showed several patrol vehicles along Helms Place, just off the Santa Monica (10) Freeway.

It wasn't clear how many people the police were searching for because the victims were "not cooperating with police."

Video from the scene showed officers in protective tactical gear with guns drawn in front of a home on Kramerwood Place. Police detained two women and one man for questioning.

Campus officials lifted the lockdown at Hamilton High School just before 11 a.m., an LAUSD spokeswoman said.

Three victims, all men or boys, were taken to the hospital critical condition, police said. One of the three died in the hostipal Wednesday afternoon.