A man convicted of beating his mother to death with a dumbbell inside their New Jersey home has been sentenced to 40 years in prison.

Union County prosecutors say John Quackenbush was sentenced Friday.

The 47-year-old Plainfield resident was convicted in February of killing 69-year-old Gail Vandewalle. Police found her body under a blanket in 2013 when they went to check on her welfare.

Quackenbush was arrested the next day at a motel in nearby Green Brook.

An autopsy determined the mother died of blunt-force trauma to the head caused by a 12-pound dumbbell. No motive for the attack has been disclosed.

Quackenbush was accused of using his dead mother's bank card at bars and liquor stores. He was convicted of weapons offenses and theft.

He acknowledged taking the bank card but said he was authorized to use it.