Maryland State Police and Washington County sheriff's deputies searched the area but found no sign of Carpenter, authorities said.
"I haven't seen him since they put him away," said Roy F. Saunders, Carpenter's uncle. "I can't see why he was ever given a weekend pass to visit anyone after what he did to my mother."
Saunders, who lives in Leitersburg, said he was not swayed by officials' assurances that Carpenter is not a threat to the public.
"It's a powder keg. It will blow one day," he said. "He killed my mother for no reason."
In 1982, Carpenter used a shotgun at close range to kill Vada Viola Carpenter. Then 17, he lived with his grandmother and called her "Mom." He later confessed to the slaying and was sentenced to life in prison.
Officials at the Patuxent Institution in Jessup, Md., said Carpenter has spent virtually his entire adult life in counseling and has gradually earned freedoms that included overnight passes on weekends and work-release.
Dr. Henry Richards, associate director of Patuxent, said the institution's Board of Review approves such privileges after an extensive process in which the victim's family must be contacted. He said family members have written letters requesting Carpenter be given leave.
Richards also pointed out that Carpenter has no other criminal record and exhibited exemplary behavior in the prison.
"This guy doesn't know how to live a life of crime," he said.
But some relatives voiced serious doubts.
"If you did it once, who's to say you're not going to do it again," said Patrick Haines, who is Carpenter's cousin.
Haines, 30, of Clear Spring, said his mother is concerned because she lives on the same road his grandmother did. He said there is no way to tell that his cousin will not kill again.
"He could. He killed our grandmother," he said. "He ought to be in prison and serve his sentence. That's where he ought to be."
Carpenter became eligible for parole in 1993.
Family members were not the only ones outraged that Carpenter was given such broad freedoms. Victims' rights advocates in Washington County and across the state lambasted the state's policy.
"It's making the hair on the back of my neck stand up. The system does not protect the right people. It's all messed up," said Halfway resident Eva Seiler, whose brother was murdered in 1983.
Seiler, a member of a national organization called the Stephanie Roper Society, said she has fought exhaustively to keep her brother's killer behind bars.
"I can see where the family would feel betrayed by the system," she said. "This guy should not have been able to earn these kinds of privileges."