Teen saw ‘devil in disguise’ John Wayne Gacy before her friend disappeared forever

Kim Byers will never forget the strange contractor who walked into her job and later murdered her childhood friend.

On Dec. 11, 1978, John Wayne Gacy walked into Nisson Pharmacy in Des Plaines, Illinois, to take measurements for what he called “a possible facelift,” or a remodeling job for the store owner. Robert Piest, a local high school student and part-time employee, was working alongside Byers — his friend and classmate. It would be the last time she ever saw him alive.

Gacy was convicted of killing 33 young men and boys in the Chicago area during the 1970s. Most of the victims’ remains were discovered by authorities in a crawl space beneath his home or buried elsewhere on the property.

‘QUEEN OF THE SERIAL KILLERS’ CONFESSED TO MULTIPLE MURDERS AFTER GIRLFRIEND’S POLICE BETRAYAL

His case has been the subject of numerous documentaries, books and shows, most recently, Peacock’s scripted series, “Devil in Disguise: John Wayne Gacy.” Byers’ daughter, Courtney Lund O’Neil, previously wrote a book, “Postmortem,” which explores how Byers gave key details that led to Gacy’s capture.

“She bumped into John Wayne Gacy the night he took Rob,” O’Neil told Fox News Digital. “He wasn’t a nice guy. It almost seemed like he was there with a plan when you reflect on it — and she wasn’t of interest to him. But I do think he was watching Rob, and that’s why he came back later that night.”

In the book, Gacy is described as “a large man, overweight, his slightly receding brown hair laced with silver.” He refused to acknowledge Byers. When they bumped into each other in the pharmacy aisles, she looked into his eyes — a “dark omen indigo.”

WATCH: JOHN WAYNE GACY’S LAWYER EXPLAINS WHY SHE BELIEVES THERE ARE MORE VICTIMS

That chilly evening, Byers asked Piest, 15, if she could borrow his blue parka. While wearing it, she filled out a form to develop a roll of film and slipped it into the coat pocket. At the end of his shift, Piest asked for his jacket back to take out the trash. The contractor then returned to retrieve his forgotten appointment book.

He “lingered, noticing Rob,” O’Neil wrote. Gacy kept watching Piest as he pretended to browse the shelves. The killer often hired high school students for projects and took note of Piest’s work ethic and build.

Piest was eager to get home — it was his mother’s birthday. But the contractor offered him a summer job paying $5 an hour, double the $2.50 minimum wage at the time. Piest was intrigued.

He assured his mother he would be home in time to celebrate. She was anxious to blow out her candles with the family. Piest left Nisson Pharmacy — and never returned.

FOLLOW THE FOX TRUE CRIME TEAM ON X

“Rob was taken on his mother’s birthday,” said O’Neil. “I always thought how horrifying that was for her — being a mother — and for the whole family. Rob loved his family and was excited to celebrate with his mom that night. And this one man destroyed everything. My mom saw her friend Rob leave with Gacy that night, and it changed her life.”

It wasn’t until the next day that an officer visited Byers and told her Piest never came home.

“This was a boy who went on nature walks and bought soda pop,” O’Neil said. “He was on his way to becoming an Eagle Scout. He was a family guy who loved gymnastics, canoeing and school. Rob was active and well-liked — the youngest in his family, full of dreams. He wanted to buy a Jeep for his first car when he turned 16 that spring. He was just a really good friend.”

When investigators searched Gacy’s home, they found disturbing oddities — clown paintings, a hallway painted in bizarre yellow-and-brown zigzags, and a trap door leading to a crawl space. They also discovered startling mementos: a Maine West High School class ring, a pistol, handcuffs, keys and an ID that wasn’t Gacy’s. A film receipt from Nisson Pharmacy turned up among the evidence.

Police called the Byers home and asked the teen to come in for a statement. Byers later wrote about the roll of film she developed.

O’Neil said there was never any question her mother would cooperate with authorities, hoping her memories might help solve what happened to her friend.

SIGN UP TO GET THE TRUE CRIME NEWSLETTER

“This was very scary to do at this time,” she said. “Being a young woman, her gender and her age were often used against her by authority figures. It wasn’t a time when a 17-year-old’s voice held a lot of weight.”

Byers’ receipt became a key piece of evidence during the investigation of Gacy, People magazine reported. According to the outlet, Gacy denied to police that he’d ever met Piest. But the police, who had Byers’ receipt in their possession, knew he was lying.

Police increased surveillance on Gacy. Inconsistencies in his statements, along with new evidence, led to a full search of his home. That’s when authorities uncovered human remains in the crawl space. Gacy eventually confessed to killing dozens of young men and boys.

Piest’s blue parka was also found.

Though Gacy is frequently mythologized as a calculating serial killer, O’Neil countered that perception, pointing out he was “quite boring.”

“I believe he managed a KFC. So what?” she explained. “He had his own construction business. Well, a lot of people do that. He was interested in politics. So are many other people. He had a picture with the first lady. Many people pose with celebrities. None of this is interesting on its own. 

“Even when they later studied his brain, there was nothing interesting to be found. It was quite a bland, boring brain. So I remind people in my book not to put serial killers on pedestals, but to actually look at them for who they are. And a lot of things about serial killers get amplified in a way that can be dangerous. It makes people obsessed.”

GET REAL-TIME UPDATES DIRECTLY ON THE TRUE CRIME HUB

“I think he was very clearly a master manipulator,” she continued. “He had charisma, and he could talk himself into and out of anything. And he had done that for the past murders before Rob Piest. With today’s technology, Gacy couldn’t do any of this successfully. But the fact that he was a leader in his community, charismatic and manipulative, made it a perfect storm for him to hide in plain sight for so long.”

As crews dug through Gacy’s property, they uncovered bodies stacked beneath the home. Piest’s body wasn’t among them. Gacy admitted dumping other victims in the Des Plaines River after running out of space.

Police divers later recovered several remains from the river. Piest, who is believed to be Gacy’s final and youngest known victim, was identified through dental records.

Between 1972 and 1978, Gacy worked as “Pogo the Clown” at children’s parties. He also lured his victims to his home, where he murdered them. In 1980, Gacy was convicted of killing 33 young men and boys, making him one of the most prolific serial killers in U.S. history.

“Even when they went to trial in 1980, my mother tried to make eye contact with Gacy when she took the stand,” said O’Neil. “He wouldn’t look at her. He told authorities when the investigation began that she was just a teen girl who wasn’t telling the truth. He insisted he never talked to a guy named Rob who worked at the pharmacy with her. But she knew.”

O’Neil said the case haunted her mother for years. She often wondered — if that film receipt hadn’t been found, how long would it have taken to stop Gacy?

In 1995, Gacy was executed by lethal injection at age 52.

CLICK HERE TO GET THE FOX NEWS APP

“My mom always remembered Rob’s love for his family,” said O’Neil. “He loved his family more than anything. He was just a kid who had so much life ahead of him. It was all just taken away.”

“As a little girl, my mom would always tell me to be careful about men who wanted to speak with me while I was riding my bicycle,” she reflected. “We were always on alert. I always felt something had happened. It wasn’t until I got older that I learned what happened, how she lost her friend one night.”

By mfnnews