after with a man in handcuffs and handed him off to other officers who led him to a waiting car, the woman said.

The woman, who said she has lived on the block for years, said she had never before seen the man, who had a medium build and appeared to be in his early 20s. Also taken into custody at the house was a 19-year-old woman who lives in one of the nearby apartments, the neighbor said.

Police sources declined to identify the man, saying only that he is thought to be the one who shot the students during a robbery. They did not give details on how investigators identified him, but one described the case against him as "very, very strong."

A police source who requested anonymity because theinvestigation is ongoing said ballistics tests on shell casings recovered at the scene of the killings show they were fired from the same gun used in two other shootings.

Detectives working on the two previous shootings had followed some "very tenuous" leads that led them to believe the man taken into custody might have been involved, the source said. The source added that the man did not have an extensive criminal record.

The source said police knew the man had been in possession of something that "could very readily be tied to one of the victims."

The second man was taken into custody in the Antelope Valley a few hours after the first man, police sources said. He is accused of being present during the robbery. Police are planning to seek