Police downgraded the death toll from a shooting spree in Santa Monica on Friday to four in addition to the gunman, who was shot dead by police in a community college library. Five other people were wounded, one of them critically in the rampage.

Santa Monica Police Sergeant Richard Lewis said two people were killed at a residence and two others were shot later at separate locations before the gunman was killed. Police had earlier put the death toll at six plus the gunman.

Officials said the discrepancy occurred because of conflicting witness accounts. They added that one of the wounded remains in critical condition.

The police also said they now believe the alleged gunman acted alone and that a man detained earlier today was not involved in the rampage.

The two bodies found in a burning Santa Monica house – the starting point in the rampage – are believed to be the brother and father of the gunman, law enforcement sources told The Times.

He was killed by officers at Santa Monica College. Police don’t have a motive for the shootings. The shootings and fire appear to have stemmed from a family dispute, but the sources said police are still unsure what happened.

Santa Monica College remained closed, and police were converging on an apartment in Mar Vista as part of the investigation.

The killing spree marked the latest in string of high-profile mass shootings over the past year, including a December attack in Connecticut that killed 20 children and six adults at an elementary school and a shooting last July at a suburban Denver movie theater that killed 12 people.

Those attacks have helped re-ignite a contentious national debate over gun violence in America that spurred Obama and his fellow Democrats nationwide to push for expanded background checks for gun buyers - an initiative defeated in the U.S. Senate.

Santa Monica Police Chief Jacqueline Seabrooks said the shooting rampage began east of the college campus shortly before noon when police received multiple reports of a house fire, a carjacking and shootings in the area.

The gunman then moved west along Pico Boulevard, firing at cars and other targets.

One person died at Cloverfield and Pico boulevards; two died at 19th Street and Pico Boulevard. Another woman died at a hospital.

Authorities shot and killed the gunman on campus. He has not yet been identified, but police described him as being 25 to 30 years old.

PURSUED ON CAMPUS

Police traded gunfire with the gunman outside the college and pursued him into a library, where he was shot and killed, Seabrooks said.

Students at the campus library described a scene of pandemonium as the sounds of gunfire rang out, sending some scurrying for cover.

One student inside the library, Cyrus Jabari, 19, said that through a window he could see a man dressed in black with a buzz-style haircut carrying what appeared to be an assault rifle.

"The only thing between me and him was a glass door," he told Reuters.

Another witness told a CNN affiliate that he saw a man drive up in a car near the campus, walk into the middle of an intersection with a gun, and open fire at passing vehicles and a building before "he jumped back in the car and took off."

"It seemed like he was alone in his car," said the witness, who was not identified by name. The witness said that he took cover under the dashboard of his car, which was struck by gunfire. "I saw him jumping out of the car. He had a big, black gun in his hand and he just started blasting maybe 10 rounds from the left to the right."