West Virginia State Police arrived at Linaburg's home at about 9:45 p.m. Wednesday night for a report of a gunshot victim. Lowrey, 32, was shot twice in the torso at close range with a .22-caliber rifle, police said.
He was pronounced dead shortly after midnight at City Hospital.
While in custody, Linaburg made statements that implicated him in the murder, police alleged.
VanMetre said Thursday evening that she had been up since 2 a.m. and not eaten all day.
"I haven't gotten a chance to call the rest of my family," she said. "We kind of have to deal with it. It's a horrific thing, but what can you do?"
Lowrey's siblings described the Charles Town native as a man who had a difficult life, spending several years in prison on theft charges.
They said they believed that Lowrey, who had been released from prison several months ago, was planning to move to Virginia, where he had completed a prison work-release program.
Family members said they learned that in recent weeks Lowrey had been staying off and on with Linaburg, with whom he had been friends for a number of years.
VanMetre said she did not know until Thursday that his friend was the same man involved in the death of her stepson-in-law almost seven years ago.
"I never even knew he was acquainted with him," she said.
Linaburg was convicted in 1994 of involuntary manslaughter in the May 1993 death of Carl Wesley Townsend III.
An argument that began inside a Martinsburg bar spilled out into the parking lot where Linaburg punched Townsend, according to court records.
A blood vessel in Linaburg's head burst and he died, court records said.
Linaburg received a one-year jail sentence on the manslaughter conviction.
Townsend's mother, Pat Townsend, expressed sympathy for Lowrey's family.
"Their loss is monumental. It never goes away, the hurt and pain," she said.
Family members said Lowrey enjoyed shooting pool and was struggling to turn his life around.
VanMetre said her half-brother was in jail when their mother died in 1989 and was not allowed to attend the funeral. His father apparently lives someplace in Florida, she said.
VanMetre said she knew Lowrey was trying to succeed.
"He had it pretty rough when he was younger," she said.