The sound of the gunshot echoed off the trailer and into the South Dakota morning, a hard crack that sent birds scattering from the trees. A spent 9mm shell casing spun onto the gravel driveway, glinting in the sun as Robert Leroy Anderson shoved the struggling young mother into his black Bronco and drove away. Two small children hid inside the house, frozen with fear, just as their mother had screamed for them to do. For hours, no one knew Piper Streily was gone.
Her husband, Vance, had been at work when he got a call that his wife hadn’t shown up for a scheduled meeting. He drove home to find a police car in his driveway, an officer standing with his four-year-old daughter Shaina and his two-year-old son Nathan. Shaina was the one who spoke first. A mean man came and took mommy.
He drove a black car. All black. What she couldn’t tell them was that her father had met that same man just days before. On the previous Friday, a stranger had knocked on the door around 7:30 in the morning.
Vance answered. He was a guy in his late twenties or early thirties, asking about a Bible camp. Vance remembered the strange vehicle he drove was a Bronco, pure flat black, even the rims and bumpers. Vance gave him a form to fill out with his name and phone number.
The man hesitated, stumbled over his own words, but wrote it down: Robert Anderson. Robert Anderson had been watching Piper Streily for weeks. He drove past her home whenever he visited his father near Lake Vermillion. He had seen her in the yard, small and pretty, a former homecoming queen now raising two kids with her husband at a small Bible camp they were starting.
He had noticed her patterns, her husband’s patterns, the family’s patterns. When he knocked on the door that Friday and saw a man instead of the woman he expected, it threw him for a loop. But he left with his name on a piece of paper. A classic mistake for a man who prided himself on planning.
But he didn’t stop. He was too far gone for that. The plan had been growing inside him for years, festering since he was a teenager sharing dark fantasies with friends about abducting and raping and killing women. His father had taught him that women were objects, and Robert had taken that lesson and built an entire secret world around it.
He was intelligent, an engineering student who performed well in school, a refrigeration technician at the John Morrell meat packing plant. He had a wife and a family. Friends and coworkers saw a normal man. But beneath the surface, he was consumed with one thought: finding another woman.
Two years earlier, in 1994, he had already succeeded once. Her name was Lissa Demansky. She had come to America from Ukraine with her husband Bill and their two young children, seeking a better life. She was working the night shift at the meat packing plant when Anderson set his sights on her.
He had enlisted a friend, Glenn Walker, to help. They flattened her tire in the massive parking lot as she worked her shift. When she came out around 1:00 in the morning, alone in the far corner of the lot, Anderson grabbed her from behind. Walker helped wrap duct tape around her hands and feet, and they forced her into the trunk.
But as they drove away, Walker got cold feet. I want out of this, he said. Anderson didn’t need him anymore. He dropped Walker off at his house and took Lissa to a secluded spot near Lake Vermillion.
He tortured her, wrapped duct tape around her head and mouth, leaving her eyes open, and she suffocated. Then he buried her in a shallow grave with Walker’s help, ensuring his friend was incriminated enough to stay quiet. Bill Demansky reported his wife missing that morning. He found her minivan in the parking lot, a flat tire, her keys still dangling from the door lock.
Police launched an investigation, but Lissa had simply vanished. The case went cold. Emboldened by his success, Anderson tried again just three months later. He had grown bolder, devising new methods like tire poppers, sharpened objects he would lay in the road while an accomplice with walkie-talkies coordinated the ambush.
Late one night in November 1994, he targeted a young businesswoman named Amy Anderson, no relation. She was driving a friend home when another car pulled in front of her, then dropped back, then passed again. It was a cat-and-mouse game, and Amy wanted nothing more than to get away. Then she heard a clunk underneath her car.
She pulled over to check, and her tire was going flat. She thought she could make it to a gas station. She didn’t. She pulled over, opened her trunk, and was reaching for the jack when the same car pulled up behind her.
She thought it was a good Samaritan. The man didn’t move. She reached in to grab the jack, and before she knew it, hands grabbed her from behind. She fought with all her might, pushing and screaming, and by luck the tire hadn’t gone flat quickly enough to fully disable her.
She spotted headlights approaching and flagged down the next car. The driver stopped and let her in. She was safe, but she couldn’t describe her attackers. It was dark, and there were two of them.
The police investigated. Anderson and Walker escaped suspicion. Walker was completely unnerved. He told Anderson he was out, that he would never help again.
Anderson was left on his own. He continued to hunt. For nearly two years, he bided his time, watching, planning. Then he saw Piper.
The Monday after that Friday visit, Anderson returned to the Streily home. This time he carried a 9mm pistol. He knocked on the door, and little Shaina answered. Anderson pushed his way in, meeting Piper in the hallway.
He yelled at her to get on the floor. She refused. He shoved her into a child’s bedroom, wrestling her to the ground, and handcuffed her wrists and ankles. Piper screamed to her children: Run and hide!
Run and hide! They obeyed. He carried Piper out over his shoulder. She was still fighting on the way to the vehicle, so he fired the gun near her to frighten her.
The casing spun onto the driveway. He couldn’t find it, and he had to go. He drove her to a secluded spot along the Big Sioux River, thick with vegetation and tall trees. On the way, Piper pleaded with him.
She told him she was menstruating. He said, I don’t care about that. She told him, My husband’s the only man I’ve ever been with. Please let me go.
He laughed. He had prepared for this moment. He had built a board with metal clamps and straps to secure a person for bondage. He had handcuffs and duct tape.
He raped and tortured Piper Strily slowly and repeatedly, then strangled her. When he was done, he concealed her remains and went home. It was hours before anyone realized Piper was missing. By the time police arrived at the Streily home, the county road grader operator had already come forward.
He had seen a black vehicle, flat black, completely black, driving near the Streily home earlier that day. He had met it several times over a few hours, performing U-turns and driving erratically. Later, he saw it parked by the small trailer house. He thought it was odd, so odd that he remembered it.
The pieces began to come together. The child’s testimony about the black car. The husband’s memory of the man who had come asking about the Bible camp. Vance remembered the name Robert Anderson.
Police worked overnight and tracked down the phone number of Robert’s father, Leland Anderson. Almost 2:30 in the morning, an investigator called. A groggy woman answered. The investigator made up a story about buying a car.
The woman said her son’s name was Robert Anderson, but he wasn’t there. He was at work at Morrell’s right now. The name Morrell hit the investigators like a bolt. That was the same place where Lissa Demansky had vanished from the parking lot two years ago.
They went to the plant and found the vehicle registered to Anderson. There was only one problem. It wasn’t black. It was royal blue with white racing stripes.
The witnesses, the county worker, the child, the husband, had all described a flat black vehicle. The police decided to keep an eye on Anderson anyway. They watched him leave work, followed him home, and then one investigator approached the door. I’d like you to come down to the station and answer some questions, he said.
Anderson said, Okay. No surprise. No protest. Just calm acceptance.
The investigator saw red flags immediately. A normal person would ask why, would demand to know if they were a suspect. Anderson just came along. At the station, the detectives asked about his vehicle.
Have you washed it? Anderson said, No, I recently painted it about six weeks ago. I’ve been purposefully not washing it until the paint sets. The story didn’t add up.
The flat black paint seen by witnesses was fresh, not six weeks old. The detectives obtained search warrants and told Anderson he and his family would need to stay in a motel while they searched his residence and his Bronco. Inside his home and vehicle, they found a separate toolbox. The investigators nicknamed it the torture box.
It contained ether to knock someone out, eye rings, and bindings. They found a homemade bondage board. And they found a cash register receipt for craft paint purchased on a Thursday: a 16-ounce liquid bottle of black finger paint, water-based paint meant for children’s art projects. In the vehicle, they found property with black paint on it and several spots with runs of black paint, like soap suds left in the cracks of a car after washing.
He hadn’t been able to wash it all away. One of the investigators took the receipt to the hardware store where the purchase had been made and showed it to the clerk. What is this stuff? he asked.
That’s 16-ounce black water-based paint, she said, showing him a bottle. He asked, If you thinned that out and painted it on a car, would it wash off? She looked at him. You know, you’re the second person this week who’s asked me that.
The other person said he was going to paint a friend’s car as a prank. The investigator showed her a photo. She pointed at Robert Leroy Anderson without hesitation. That’s the man who bought the black paint last Thursday.
It was the break they needed. But they still had to prove it. The investigators weren’t sure they could paint an entire Bronco with a half-bottle of that paint. So they bought another bottle.
The crime lab borrowed a red and white Bronco from a friend, thinned out the paint, and applied it to the vehicle. In about twenty minutes, the Bronco was completely flat black. Then they took it to a car wash, used a wand on it, and had it clean in seven minutes. The experiment took just over an hour.
It proved that Anderson had painted his vehicle black to commit the abduction, then washed it off to hide the evidence. The receipt, the runs of paint, the misplaced confidence, it all snapped into place. Robert Leroy Anderson was arrested and charged with the kidnapping, rape, and murder of Piper Streily. When investigators reopened Lissa Demansky’s case, the evidence pointed to him there as well.
Glenn Walker eventually came forward and cooperated with authorities, testifying about Anderson’s crimes. In 2000, Anderson pleaded guilty to multiple charges, including the murders of both Lissa Demansky and Piper Streily, and was sentenced to life in prison without the possibility of parole. He later died in custody. For the small community in South Dakota, the trial brought a measure of justice.
But for the families of the two women he killed, and for the children who witnessed their mother’s abduction, there was no closure, only the knowledge that a monster had been stopped. And it had all come down to a bottle of black fingerprint paint, an experiment that took just one hour to prove.
