County police had been exploring whether John Allen Muhammad, 41, and Lee Boyd Malvo, 17, shot and wounded the owner of a Clinton restaurant 10 days earlier, then stole $3,000 and a laptop computer from his car.
"There are similarities in the way the cases took place; both were store owners closing after hours," said Sgt. Tora Coates, a police spokeswoman. "They are less than a mile or a mile and a half from each other."
The two shooting scenes are also a short drive from the neighborhood where Muhammad's ex-wife, Mildred, lived with their three children. Neighbors recall seeing Muhammad's blue 1990 Chevrolet Caprice in the area several times.
The sniper task force is studying the evidence, presumably including the computer, to see whether the cases are related to the sniper shootings, Prince George's police said. Muhammad and Malvo had a laptop computer when they were arrested Oct. 24.
Word that the number of cross-country shootings attributed to the pair could grow -- these would be the 18th and 19th shooting episodes linked to them -- came on a day when Malvo appeared in a Baltimore courtroom.
Malvo went before U.S. Magistrate Judge James K. Bredar for a detention hearing. The proceedings were closed to the public, with the courtroom windows covered with paper and guards stationed outside for the two-hour hearing.
Muhammad is scheduled to appear at a public detention hearing today in U.S. District Court in Greenbelt. He was charged last week in a 20-count criminal complaint in connection with the sniper shootings.
Also yesterday, a spokesman for the Jamaican Embassy said a man who had been held as a material witness in the investigation was released from federal custody Friday.
Nathanel O. Osbourne helped Muhammad buy the Caprice investigators say was involved in the attacks. Federal authorities held Osbourne for a week but filed no charges, said O'Neil Hamilton, the spokesman.
Muhammad and Malvo are charged or suspected in the deaths of 13 people -- 10 in the Washington area, and one each in Montgomery, Ala., Baton Rouge, La., and Tacoma, Wash.
Last week, police in Montgomery County linked a Sept. 14 shooting outside a Silver Spring beer and wine store to Muhammad and Malvo. Rupinder "Bennie" Oberoi, 22, of Linthicum was wounded about 10:15 p.m. while locking up the shop.
The shooting police discussed yesterday occurred the next night, also at 10:15. Muhammad Rashid was locking up Three Road Liquors in Clinton when two shots rang out. Both bullets hit the store. As Rashid turned around, a man ran up and shot him in the abdomen with a pistol, he said.
The man took his wallet and fled. In the darkness, Rashid, 32, did not get a good enough look at the gunman to say if it might have been Muhammad or Malvo.
Moments earlier, Rashid saw a "big American car" with dark-colored paint parked nearby.
Store owner Harpal Bhatti said police found one bullet in the store, and surgeons removed another from Rashid.
Malvo's hearing was attended by his court-appointed attorneys, federal prosecutors and federal law enforcement agents. No other witnesses entered the courtroom to testify.
Malvo's status in the federal system has been shrouded in secrecy because of his age. Justice Department officials declined to comment. On Friday, Bredar rejected a request by news organizations to open the hearing.
After the hearing, Baltimore attorney Joshua R. Treem, appointed to represent Malvo, said: "The juvenile was ordered detained. I can't address anything more than what I've just said. I'm sorry."
Federal prosecutors have until Thursday to secure an indictment against Muhammad. Federal law allows a longer period for authorities to decide whether they will seek to have a juvenile defendant tried as an adult in U.S. courts.
Justice Department officials are expected to decide this week whether the two will be tried first in the federal court system or transferred to state courts in Virginia or Maryland.