Authorities charged the two Beltway Sniper suspects with murder Thursday in a Louisiana shooting that came just two days after a similar slaying in Alabama.
Officials in Alabama also said they had definitively linked the two men to the Alabama murder.
John Allen Muhammad, 41, and John Lee Malvo, 17, are now charged with a month-long series of killings stretching from the Gulf Coast to the suburbs of the nation's capital. Police nationwide are looking for links to the men with help from federal authorities.
The two suspects face multiple state and federal counts in the Alabama and Louisiana cases, as well as the sniper spree that left 10 people dead and three others wounded in Maryland, Virginia and Washington, D.C. They are also suspects in a February killing in Washington state.
Baton Rouge Police Chief Pat Englade issued first-degree murder warrants for Muhammad and Malvo after ballistics tests matched the rifle used in the sniper shootings to a Sept. 23 slaying and robbery in the Louisiana capital.
Hong Im Ballenger, 45, died from a single shot to the head as she left the Beauty Depot. Witnesses said the gunman was a young black man who fled into a nearby park and evaded bloodhounds called in to track him down.
"Ballistic comparisons link this murder to several of [the] D.C.-area killings," Englade said.
According to the arrest warrant, police believe Muhammad shot the woman and Malvo stole her purse and fled.
Earlier in the day, Alabama authorities said the same rifle, a .223-caliber Bushmaster, had been linked to the shooting death of a liquor store worker in Montgomery on Sept. 21, two days before the Louisiana slaying and 315 miles away.
In that case, the suspect -- allegedly Malvo -- was seen rifling through one of the victim's purses before he was chased off by a police officer.
The sniper suspects have been in custody in Maryland since they were captured at a highway rest stop Oct. 24. Authorities found the rifle in their car, which they say was modified so someone could fire unseen through a hole in the trunk.
In Washington, Attorney General John Ashcroft said the investigation was continuing into the possibility other people may be involved or that the suspects have committed more crimes.
"We will proceed deliberatively, cautiously and not jump to any conclusions," Ashcroft said. "The facts ... will determine the final outcome and we intend to follow the facts wherever they may lead."
A senior Justice Department official, speaking on condition of anonymity, said there was no specific evidence showing others were involved but authorities would not rule out the possibility.
Police nationwide are checking unsolved crimes for links to the sniper suspects, the official said, with a particular focus on the Gulf Coast and East Coast. Ashcroft is considering whether the federal government will take the lead in prosecuting the two men.
In Alabama, officials said ballistics evidence had linked the rifle to Claudine Parker, 52, who was shot to death during an attack that also wounded her liquor store co-worker, Kellie Adams, 24.
State forensics director Taylor Noggle said the slug taken from Parker's body matched bullets test fired from the Bushmaster. Muhammad and Malvo have already been charged with capital murder in the crime.
Muhammad grew up in Baton Rouge and still has relatives and friends there, including one of his ex-wives. He visited the area this summer, friends said.
Englade said the unusual type of bullet used to kill Ballenger led police to investigate a possible link. Police also said dated receipts from two Baton Rouge stores were found in the suspects' car.
Jim Ballenger, the victim's husband, said his wife was a native of Inchon, South Korea, and the two were married in the Asian nation when he was in the military. The couple moved to Baton Rouge in 1996 with their three sons.
At a church Halloween party Thursday, Ballenger said was at peace with what happened.
"I know my wife is in heaven," he said. "Jesus said to forgive and I am born again. The man who did it needs to do time in jail."
First-degree murder carries a possible death penalty in Louisiana. Doug Moreau, the Baton Rouge district attorney, said he did not know when he would get the case and did not know whether he would push for the death penalty.
A task force working on the serial killings of three Baton Rouge women in the past year is working to obtain DNA evidence from Muhammad and Malvo. However, the two have not been linked to those killings, Englade said.
-- Officials in Prince Georges County, Md., where a 13-year-old boy was wounded outside his school, charged Muhammad and Malvo with attempted murder and conspiracy to commit murder, both of which carry life sentences.
-- The Seattle Times reported that a Tacoma mechanic planned to pay Muhammad $3,000 for a set of fake documents, including a passport and visa, so he could drive after drunken-driving offenses.
The mechanic, Craig Hack, 41, said Muhammad described himself seven months ago as "a broker" in the sale of fake identification. He said the plan was halted by Muhammad's arrest.
The Associated Press contributed to this report.