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A young college student who was brutally killed on a Prescott hiking trail decades ago was the victim of a serial predator who took his own life years later, authorities said Friday.

Yavapai County Sheriff David Rhodes announced at a news conference that DNA evidence indicates Bryan Scott Bennett was the man responsible for 23-year-old Catherine “Cathy” Sposito's death in 1987.

In November 2022, authorities had the body of Bennett, who killed himself in 1994, exhumed. It wasn't until March that investigators confirmed DNA on a wrench used in the slaying belonged to him.

By releasing this news, authorities hope to determine whether there were other victims in addition to Sposito and three other women who authorities believe Bennett attacked.

“What we know of serious violent predators like this, it is very unlikely given the frequency in which he was willing to act that these are the only four cases that exist,” Rhodes said.

Violent attack on Thumb Butte Trail

Sposito was hiking on Thumb Butte Trail near downtown Prescott in the early morning of June 13, 1987, when she was attacked. Sposito was hit in the head with a rock and a wrench, shot in the eye and then stabbed in the head, according to investigators.

Other hikers actually heard her scream for help but she was dead by the time they got to her, Rhodes said.

Sposito’s killing rocked Prescott and Yavapai County as Thumb Butte Trail had always been seen as safe.

Bennett was a junior at Prescott High School at the time of her death. He had moved from Calvin, Kentucky, and only spent a year and a half there before withdrawing from school, Rhodes said.

Authorities now believe he was behind a 1990 sexual assault of another woman on the same trail at the same time of day.

Series of assaults

Two months after that incident, Bennett allegedly locked a girl in a room at a Chino Valley house party and tried to sexually assault her. He was arrested, Rhodes said, but was later acquitted.

In June 1993, Bennett allegedly kidnapped a woman at a Prescott post office at knifepoint. Authorities say he sexually assaulted her several times. The victim was rescued when police happened to pull over the car they were in. Bennett was arrested but was never convicted of anything, Rhodes said.

A year later, Bennett moved back to Kentucky and died by suicide using a .22-caliber gun, the same kind of firearm used on Sposito. But Rhodes said it is unknown whether it was the same gun.

In 2017, advanced and more accessible DNA technology led investigators to identify a descendant of Bennett and link it to the second attack on Thumb Butte Trail. They then worked back to Sposito's case.