Updated

Authorities said Monday that they had linked John Allen Muhammad and John Lee Malvo to the Tacoma shooting death of a 21-year-old woman whose aunt once worked for Muhammad's auto repair business.

Muhammad and Malvo, who face charges in Virginia and Maryland in the Washington, D.C., area sniper killings, also have been linked to a shooting last spring at a synagogue here in which no one was injured, Tacoma police and representatives of the federal Bureau of Alcohol, Tobacco and Firearms said at a news conference.

Police Chief David Brame said the break in the investigation came when a local man contacted the FBI last week. The man told authorities he'd allowed Muhammad and Malvo to borrow his weapons, including a .45-caliber semiautomatic handgun, while the pair were staying with him earlier this year.

"As a result, we now consider John Allen Muhammad and John Lee Malvo as suspects in the Keenya Cook homicide," Brame said.

Investigators recovered three handguns and two rifles from the man, including two allegedly used in the crimes, Tacoma police spokesman Jim Mattheis said. Ballistics tests confirmed that both weapons were used in separate shootings, he said.

Cook was shot in the face last Feb. 16 when she opened the door to the house where she lived.

Mattheis has said Cook's family recognized Muhammad from news photos after his arrest in the sniper cases and called authorities.

The man who provided police with the weapons also "came forward after the news coverage," Mattheis said. "He's been very cooperative."

Cook's aunt, Isa Nichols, used to be a bookkeeper for Muhammad's auto repair business in the 1990s. Nichols became friends with Muhammad and his then-wife Mildred, and sided with Mildred during that couple's bitter divorce and child-custody dispute.

Cook had moved into Nichols' home in the fall of 2001 for protection from an abusive boyfriend. Members of Cook's family wondered if Isa Nichols was the intended target and that Cook was shot by mistake when she opened the door.

In the synagogue case, Brame said a .44-caliber Magnum, borrowed from the same man, was used in a shooting at Temple Beth El between May 1 and May 4. No one was believed at the synagogue at the time.

Brame said there are no plans to charge the man who came forward.

Muhammad, 41, and Malvo, 17, have been charged with numerous sniper shootings in the suburbs of Washington, D.C., in the last month. The three-week string of attacks left 10 dead and three others wounded in Virginia, Maryland and the District of Columbia.

Muhammad was in the Army at Fort Lewis starting in 1985 and lived in Tacoma off and on after he was honorably discharged from the Army in 1994.

The Tacoma police informant told officers Muhammad and Malvo stayed with him occasionally between February and April of this year, then became full-time guests at his home from May until July.