JACKSONVILLE, Fla. -

A 57-year-old Jacksonville man was arrested and charged in the stabbing death of his girlfriend Sunday night.

Police said Thomas Webster stabbed 54-year-old Patricia Berner (pictured, below) once with a kitchen knife during an argument.

Police were called to the home on Millpoint Road off Old St. Augustine Road in Mandarin around 7 p.m. Sunday.

Patricia Berner Investigators said Webster went to a nearby Kangaroo store and told the clerk he may have killed his girlfriend. The clerk then called 911.

"Usually we don't go to a call like that and someone's telling you, 'I killed someone,'" JSO Lt. Rob Schoonover said. "In this case, it did happen."

Webster had been drinking alcohol he purchased at the store earlier in the day, police said.

They said the couple was in the process of moving out of the home.

Ophelia Lane says she was friendly with her neighbor and used to see him often in their quiet Mandarin neighborhood.

"You just can't predict what people are going to do today," neighbor Ophelia Lane said. "You can't tell by looking at them what they will do."

Neighbors say Berner was planning on moving to South Florida to take care of her ailing mother. They say they saw Berner on Sunday and are finding it hard to believe she's no longer alive.

"Yesterday morning when I was going to church, she was putting things in her car," neighbor Mary Bell said. "She was moving down south to be with her mother who was ill, a bad situation."

"She was a sweet person," a neighbor named Sandy said. "I don't know what he was."