DAYTONA BEACH, Fla. — David Mohney wanted big changes for his family: to end his turbulent marriage, move his children 1,900 miles from Florida to South Dakota and transition from being a stay-at-home dad to starting work as a chiropractor.

Instead, authorities say, 52-year-old Mohney reached for a gun after arguing with his wife and shot all three of their children before killing himself. The couple’s youngest, a 9-year-old daughter, survived. But both of her siblings died along with their father.

“If he wants to commit suicide, let him commit suicide. To shoot the children, that’s cowardly,” Volusia County Sheriff Ben Johnson said outside the family’s home hours after the slayings occurred before dawn Friday.

The slayings occurred as David and Cynthia Mohney were entrenched in a bitter divorce after nearly 25 years of marriage. Court filings showed David Mohney wanted to leave his wife and move with their children to South Dakota. He had recently finished chiropractic school while she supported the family working as a physician’s assistant, making $220,000.