The family of Isaiah McLaughlin, who was a passenger in a pickup truck involved in the accident, filed suit in Tarrant County, Texas, Civil Court this week, the sixth suit against Ethan Crouch, 16, and his parents, the Fort Worth Star-Telegram reported Thursday.
The suit also mentions the Crouch family business, Cleburne Metal Works.
Crouch was sentenced in county juvenile court to 10 years probation and intensive therapy after he admitted causing the crash.
Local youth minister Brian Jennings stopped to help a stranded motorist on the night of June 15, with McLaughlin and another youth, Lucas McConnell, in his vehicle. Crouch, driving a pickup truck owned by his father's company while he had a blood alcohol level three times the legal limit, struck the stranded motorist's vehicle and hit the driver and three people trying to help her.
Crouch's truck, with seven other teens aboard including two in the pickup bed, then struck Jennings' vehicle before flipping over and crashing into a tree, the newspaper said.
Jennings was killed, as were Breanna Mitchell, 24, the driver of the stranded car; and Hollie Boyles, 52, and her daughter Shelby Boyles, 21, nearby residents who had come from their home to help.
Crouch was sentenced Dec. 10, came after he admitted responsibility, the state juvenile equivalent of pleading guilty, to four counts of intoxication manslaughter and two counts of intoxication assault.
In court testimony he was described as a spoiled teenager from a wealthy but dysfunctional family, the newspaper said, noting a psychologist testified described Crouch was a victim of "affluenza," a mental state of irresponsible behavior brought on by wealth.