Allen Fryer was born in 1944 and raised in Sioux Falls, South Dakota, along with his younger brothers, David and James. Very little is publicly recorded about Allen's early life, education, or employment, though it is known that at the time of the Gitchie Manitou murders, he was employed as a farmhand for a local farmer. Fryer was 29 years old at the time of the crimes, significantly older than his teenage victims, and was seen as the ringleader among his brothers.

Known to Sandra Cheskey as "the boss," Allen displayed a commanding and manipulative presence during the group's deadly rampage. While his brothers carried out parts of the crime, Allen maintained control of the situation and the victims, posing as a law enforcement officer and using that lie to justify and facilitate the kidnappings and killings. Despite a façade of authority, Allen’s actions were brutal, calculated, and deeply sadistic. His behavior would later be described as predatory and remorseless.

Allen’s employer would unwittingly play a key role in the investigation when the property—used to imprison and rape Sandra Cheskey—was identified by a unique red fuel tank on-site, directly linking Fryer to the crime. His truck, recognized by Cheskey during a ride with the sheriff, would also place him at the center of the criminal investigation.

On the night of November 17, 1973, five teenagers from Sioux Falls, South Dakota, were camping at Gitchie Manitou State Preserve in Iowa when they were ambushed by three armed men—brothers Allen, David, and James Fryer. Believing the teens were using marijuana, the Fryer brothers intended to rob them. But what began as a drug robbery quickly spiraled into cold-blooded murder.

The ambush began with the Fryers opening fire from a ridge above the teenagers’ campfire. Roger Essem, 17, was killed instantly. Stewart Baade, 18, was critically wounded. The others ran into the woods, terrified. The Fryers posed as law enforcement officers and coaxed Michael Hadrath, 15, and Sandra Cheskey, 13, out of hiding. Allen shot Michael in the arm before corralling the group and binding Sandra, who was then placed in the back of a pickup truck. Allen drove her away from the scene, still claiming to be a cop.

Meanwhile, James and David executed Stewart Baade, Michael Hadrath, and Dana Baade, 14, at close range with shotguns. Their bodies were later discovered by visitors to the park.

Sandra Cheskey was taken by Allen to a nearby abandoned farmhouse, where she was held captive. James Fryer later arrived and raped her. Allen returned, making chilling comments and attempting to lure her into the farmhouse again under the pretense of “looking for critters.” She refused. Allen eventually drove Sandra home, continuing to act like an officer of the law.

Two days later, the victims' bodies were recovered, and a murder investigation began. Sandra’s recollection of events—remarkably calm, clear, and specific for a 13-year-old—was initially doubted by investigators. But she passed a polygraph test and helped locate the farmhouse using a memory of the large red fuel tank on the property. By chance, she and the sheriff spotted Allen Fryer driving by in the very truck used during the crime.

Allen was arrested on November 29, 1973, and his brothers were quickly taken into custody afterward. Though Allen initially tried to shift the blame onto the victims, his story unraveled under interrogation. He ultimately admitted involvement, justifying the murders by accusing the teens of drinking and smoking marijuana.

Allen was deemed fit for trial following psychiatric testing. In May 1974, he was found guilty of four counts of first-degree murder and sentenced to four consecutive life sentences without the possibility of parole. Just weeks later, on June 18, 1974, Allen and James escaped from jail but were swiftly recaptured in Wyoming and returned to Iowa.

As of 2024, Allen Fryer remains incarcerated at the Anamosa State Penitentiary in Iowa, serving four life terms for his role in one of the most horrifying mass murders in Iowa history.