A convicted sex offender was sentenced to 12 years in prison Friday for abusing his girlfriend’s cats and dogs, the Boulder District Attorney’s Office said.

Shortly after being released from a halfway house, Nathaniel Stark, now 27 and listed as a Longmont resident, moved in with his girlfriend in August 2019. Her animals then started showing signs of injuries, the office said.

Within three months of the couple living together, two of her cats had died. Veterinarians concluded one of the cats died of head trauma and strangulation, the office said.

In February 2020, Stark severely beat his girlfriend’s dog, the office said.

Authorities removed the dog from their custody.

Police arrested Stark in October 2020 for violating a bond for having contact with animals. Stark fled the state, and was brought back to Colorado, the office said.

“This case involved terrible conduct against animals,” District Attorney Michael Dougherty said in a statement. “Given his prior conduct and the cruel acts involving his partner’s pets, the defendant clearly presented a risk to others.”

In May 2022, Stark entered a guilty plea to one count of aggravated cruelty to animals and a guilty plea to failing to verify his location as a sex offender.

In January 2018, the court had deemed Stark a “sexually violent predator” and sentenced him to 10 years of sex offender intensive supervision probation.

“The defendant’s abuse of his partner’s animals in this case was just one act of violence in his criminal history,” Deputy District Attorney Jenny McClintock said. “It is important to take these cases seriously as they involve victims who have no voice and are often used as coercive controlling tactics in a domestic violence relationship.”