During the early 1990s, fear spread across Phoenix, Arizona, due to a series of vicious attacks on young female cyclists along the city’s canal trails.

The tragedies involved two young women: a 21-year-old emerging tech talent and a 17-year-old high school student, both found dead ten months apart. Each victim had been brutally stabbed and showed evidence of sexual assault.

The horrifying nature of these crimes shocked even the most seasoned investigators as they raced to catch the mysterious assailant, as reported in the “On the Hunt for the Zombie Hunter” segment of Dateline: Secrets Uncovered. It took many years and clever police strategies to finally connect the murders to a suspect known as “The Zombie Hunter.” (This story was also featured on Snapped.)

Then, just 10 months after Brosso was killed, Phoenix mom Charlotte Pottle was out on an early morning bike ride in September of 1993 with her sister and their children when she spotted a large pool of liquid in the path. Pottle couldn’t make out what it was until the small group was on their way back home and she noticed it had a distinctive red hue. 

Next to the large blood stain, Pottle noticed what looked like drag marks that led off the trail toward the canal. 

“You just have this eerie feeling about you like… you need to get out,” she said of the chilling discovery.

DNA shows both victims killed by same man

For months, plain clothes police officers took to the trails in the hopes of unmasking the killer or killers, but after lead after lead was eliminated, the cases eventually went cold. 

In 2000, advances in technology confirmed the investigators’ suspicions that the DNA left on both women’s bodies matched to the same killer. The unknown attacker’s DNA was uploaded to CODIS, a national DNA database, but there were no matches and the case cooled once again. 

Then, in 2011, Sgt. Troy Hillman, the head of the Phoenix Police Department’s cold case unit, decided to take a new look at the case files.

“Something truly evil” 

“I remember reading word for word and I was traumatized by what I read,” Hillman said. “It was almost as if I was reading about something truly evil.” 

In the years that followed, Hillman admittedly became “obsessed” with the case. By then, approximately 800 people had been interviewed. Although DNA samples had been taken from some of those people, Hillman and his team set out to fly across the country collecting more samples to rule out others in the files. 

He turned to forensic experts in the Vidocq Society in Philadelphia for help creating a profile of the killer and learned that their suspect was likely a Phoenix resident who liked to act out fantasies and could already be in the case files.

Then in 2014, years before the use of genetic genealogy would make headlines for its role bringing down California’s Golden State Killer, the Phoenix Police Department got a call from forensic genealogist Colleen Fitzpatrick, who believed she might be able to use the killer’s DNA profile to identify the suspect’s relatives through the use of public genealogy websites.

At the time, the science was just emerging and it took three months for Hillman to convince police leadership to fund the experimental tactic. The move paid off when just a few weeks later, Fitzpatrick called and told him that she believed the killer had the surname “Miller.” 

A suspect emerges

The lead sent Hillman scrambling back to the case files to identify anyone with the last name Miller. One person clearly stood out.

Shortly after the murders, someone had called in an anonymous tip about a teenager named Bryan Patrick Miller. His roommate had allegedly seen the teen with a turquoise bodysuit much like the one found with Bernas’ body. 

Although the tip was looked into at the time, Miller was originally dismissed because of his young age.

Police find another victim 

As Hillman poured deeper into the case file, he learned that three years before the murders — when Miller was just 16 — he’d been arrested for stabbing a 24-year-old woman in the back after she got off the bus near Paradise Valley Mall. 

He was apprehended a short time later and charged with attempted murder, but given his status as a juvenile, Miller only served one year in detention.

At the time, Miller’s mother told police that she was afraid of her young son and handed over a chilling handwritten document he’d created, labeled “Plan,” which described step-by-step how to kidnap and murder a woman.

By 2014, Miller was a single dad to a teenage daughter, working at an Amazon warehouse and living in Phoenix.

The Zombie Hunter

During his free time, Miller often immersed himself in the world of steam punk, a creative science-fiction subculture centered on role playing. Miller was known as “The Zombie Hunter” and often took to the Phoenix streets or Comic-Con conventions wearing a trench coat, mask, hard hat and large fabricated gun to complete the look.

He was perhaps best known for his “Zombie Hunter” vehicle, a former police cruiser converted into his own custom creation, complete with fake blood oozing down the doors, green sirens and a Zombie dummy made to fit in the backseat behind bars.

“That really caught our attention. The fact that Bryan lived in this fantasy world,” Hillman said. 

Although Hillman believed authorities had likely found their killer, they still had to prove it, and created a sting in 2015 involving a fake job interview to collect Miller’s DNA. 

It was a match and Miller was arrested for two counts of kidnapping, attempted sexual assault and first degree murder.