CITRUS COUNTY, Fla. (WFLA) — The Citrus County Sheriff’s Office is trying to figure out what happened to a 38-year-old father who vanished three months ago.

Derek Windler’s mom filed the missing person report with the sheriff’s office in late August.

“You know he might have had some issues in the past,” Deb Evans said. “But he wouldn’t leave his son.”

Evans said she last spoke with her son on Aug. 26.

“10:30 at night and he was home and he was listening to music and he was fine,” she said.

The next morning, Evans said, his girlfriend who lived with him in Crystal River called to say they had broken up.

“She messaged me a few more times that day asking if I heard from him,” Evans recalled. “I said no.”

So far the only break in this missing person case is when deputies found Windler’s black GMC Sierra truck in Homosassa in early September.

“Do you worry something bad may have happened to him?” News Channel 8 asked Evans.

“I suspect foul play, of course,” she said.

Evans said investigators from the sheriff’s office have not been able to share much information with her because this is still an open case.

Windler’s family is offering a $15,000 reward for anyone with information to help bring him home.

“I really do think somebody knows something in this county and I wish they would come forward,” Evans said.

News Channel 8 connected Windler’s mother with We Are The Essentials, a group of former law enforcement in Tampa Bay that specializes in searching for missing people.

Anyone who has seen Windler or has information regarding his whereabouts is urged to call the Citrus County Sheriff’s Office at 352-249-2790. To remain anonymous and to be eligible for a reward, contact Crime Stoppers of Citrus County at 1-888-ANY-TIPS (888-269-8477) or online at Crime Stoppers Citrus.