CHATTANOOGA, TN — A college psychology student was charged Sunday with murdering his parents and his sister in their home in an affluent section of Hamilton County.

Investigators said the slayings came after a dispute over his use of family credit cards.

Peter Bullington, 24, was charged with three counts of first-degree murder in the deaths of his father Nigel, 50, mother, Gerardinia, 49, and his sister, Amanda, 22.

Bullington killed his family after a dispute over the family's credit card.

All three were shot to death in the family's kitchen Saturday afternoon in Apison, about 20 miles outside Chattanooga.

Sheriff John Cupp said Peter Bullington told investigators "there was a family discussion about his spending on the family's credit cards. He went upstairs and got his father's gun, came back downstairs and shot them in the kitchen area."

Cupp said Peter Bullington, a student at the University of Tennessee at Chattanooga, had "maxed out" credit cards, spending more than $5,000. He said the family was having financial problems.

"...I think there was even some talk of filing bankruptcy," the sheriff said.

All three victims had been shot multiple times.