Authorities say the .44 caliber handgun used by Charles Lee "Cookie" Thornton to kill Kirkwood, Mo., police Sgt. William Biggs may have been stolen. After killing Biggs, Thornton took the officer's .40 S&W duty weapon and used both to open fire on the St. Louis suburb's city council. Four people, including another officer, were killed in the Feb. 7 shooting before Thornton was shot and killed by police.

Investigators say that Thornton's .44 was stolen in nearby Franklin County in 1994 or 1995. How Thornton acquired the weapon is not known.

Thornton's brother Gerald told the St. Louis Post-Dispatch that he did not know how his brother came into possession of the revolver. His brother Paul speculated that the gun may have been bought illegally on the street.

"He couldn't have had it more than a week or two," Paul Thornton told the papers, adding that he thought the shootings were a "spur of the moment thing."

Charles Thornton was enraged at the government of Kirkwood over numerous parking citations and the fact that the city council had prohibited him from speaking during its meetings. The speech ban was upheld in court shortly before the shooting, which killed Sgt. Biggs, Officer Thomas Ballman, Councilwoman Connie Karr, Councilman Michael H.T. Lynch, and Public Works Director Ken Yost. Mayor Mike Swoboda and newspaper reporter Todd Smith were wounded in the attack and are recovering.