William Cumber snapped and twice struck Sabine Musil-Buehler twice in the head before choking her to death, he said in a 40-minute confession obtained by the Bradenton Herald.
Musil-Buehler's skeletal remains were found Friday on Holmes Beach, seven years after her disappearance.
The 49-year-old Anna Maria Island woman was last seen alive on Nov. 4, 2008. Cumber was charged with her murder in October 2012, and as part of a plea agreement, he gave investigators the location of the body.
Crews on Thursday night in an area off Holmes Beach found Converse tennis shoes similar to the ones Musil-Buehler was wearing when she disappeared. The skeletal remains were uncovered and identified Friday.
Cumber gave a full account of the murder to detectives in exchange for a 20-year prison sentence.
“I lose control, I hit her in the head, OK?," he says in the confession.
"With a hand or an object or what?" a detective asks.
"With my fist," Cumber replies.
Cumber said he then choked her to death.
“I couldn’t believe what I had did," Cumber says. "I stared down at her and all kinds of things were running through my mind, I couldn’t believe what I had done.”
Deciding he was not going back to prison, Cumber says in the confession, he rolled Musil-Buehler's body up in a bed sheet, put it in the back of her car, picked up a shovel from the motel she owned with her estranged husband and buried her at the end of the road.
Manatee County Sheriff Brad Steube called the murder a crime of passion.
“That argument began over him smoking cigarettes, and we believed all along she intended on leaving him, so it just escalated to the point where this occurred," Steube said.
Cumber was facing life in prison if he went to trial for second-degree murder.