Horse Farm Owner Sentenced to Life in Prison for Killing Boyfriend After Claiming Self-Defense

Kaylen Deller claimed she shot Chad Mullen in self-defense at her Florida horse farm, but the jury rejected her testimony after just one hour of deliberation.

Florida woman convicted of murdering boyfriend she buried in shallow grave

Kylen Deller, 32, was convicted of murder in the September 2024 murder of her on-again, off-again boyfriend Chad Mullen.

A Florida woman accused of murdering her boyfriend and burying him in a shallow grave has been found guilty of his murder.

Kylen Deller, 32, was charged in September 2024 with the first-degree murder of her on-again, off-again boyfriend Chad Mullen.

According to prosecutors, Deller killed Mullen at his horse ranch in San Mateo, Florida, then recruited a friend and his horse to help move the body, which was found in a shallow grave more than a month after she disappeared.

Deller was convicted of first-degree murder and sentenced to life in prison Thursday after a jury deliberated for more than an hour. He was also found guilty of tampering with evidence and failing to report the death of a person.

Sheriff: Florida woman charged with murder, fleeing police after body found in shallow grave

Chad Mullen was shot again in September 2024 by his girlfriend, Kaylen Deller. Prosecutors said Deller used a horse and enlisted a friend to help move his body before burying it in a shallow grave. (Putnam County Sheriff's Office)

On Wednesday, Deller testified that he killed Mullen in self-defense because he choked her and raised a hammer at her when she confronted him about unsubstantiated allegations that he had sexually abused his young daughter. Deler Desmoulins became enraged, pinned him to the truck and grabbed him by the throat, claiming he was unable to breathe at the time.

That's when Deller said he picked up the gun. Deller said he got the gun after Mullen broke into his apartment on Aug. 1, 2024.

"I pulled the trigger and shot him twice," Deller said. "I was terribly afraid.

Kylen Deller, 32, was convicted of first-degree murder and sentenced to life in prison for fatally shooting her boyfriend, Chad Mullen, at his horse ranch in Florida in September 2024. (Putnam County Sheriff's Office)

The woman said she did not intend to kill Mullen and believed she was defending herself.

Prosecutors then asked Deller why she chose not to call the police and why she kept in touch with Mullen even though she described him as violent, and evidence that he made 28 calls to her between September 2 and September 9, 2024.

Deller testified that he did not initially call 911 after Deller was shot because he thought the police would not believe his claim of self-defense. That's why he didn't tell the Mullen family.

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Cullen Deller was sentenced to life in prison after a jury found him guilty of first-degree murder in the murder of her boyfriend, Chad Mullen. Deller testified that he shot Mullen twice in self-defense, claiming that he had assaulted him during the argument. (WFOX)

"Probably not a good idea," Deller said. "I was more worried about getting in trouble."

During closing arguments Thursday, prosecutors said Deller should have called law enforcement.

"She could have called law enforcement to report that Mr. Mullen had assaulted her or accosted her or done something to her, but she never did," a prosecutor said.

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