After emerging as the sole survivor of a six-man party who had attempted to travel through the San Juan Mountains of the Colorado Territory, he eventually confessed to having lived off the flesh of his companions, giving more than one version of his account as to the circumstances.

Having heard of gold that had been discovered in Breckenridge, Robert McGrue found a party of twenty ready to join him and make the trip from Salt Lake City to the San Juan Mountains, south of Colorado Territory.

On the first part of the trip to the San Juan Mountains, members of McGrue's party later said that he had apparently overstated his experience of being familiar to the area, or had even possibly fabricated his qualifications altogether.

[16][17] On April 16, 1874, 65 days after his departure, Packer emerged from the woods alone and made his way across a frozen lake bed to the Los Pinós Indian Agency, near Saguache, Colorado.

Packer stayed at the agency for ten days before heading to the nearby town of Saguache, where he began to buy supplies for his journey back home in Pennsylvania.

The men were introduced to the head of the agency, General Charles Adams, who told them he had already met another member of their party by the name of Alfred Packer – and that he spoke of desertion at the hands of his companions.

The officer returned soon with news from various sources that Packer had been seen with several different wallets and had told varying stories regarding his journey, and that he had arrived in Saguache with plenty of cash, and that no one in town claimed to have lent him a penny.

As they were beginning to settle the matter, two Ute tribesmen arrived in Los Piños, holding strips of dried human flesh which they had found on a hill near the agency while hunting.

A few days after this, he left camp to gather dry firewood and returned to find four men around the slain body of Israel Swan, who had been struck in the head with a hatchet and killed instantly.

After roasting and eating their shoes and attempting to survive on what scant and edible vegetation they could find, the men, claimed Packer, entered into a pact whereby if one died, his meat would serve to save the others from starvation.

Bell wanted to kill me with his rifle—struck a tree and broke his gun.In Packer's later amended version of this story, the men had endured almost 20 days from Ouray's camp and more than 10 without any substantial food at all.

Packer elaborated that James Humphrey had also died of exposure to the extreme cold, and that George Noon was killed days later by Shannon Bell for the sole purpose of food, after there was no more substantial meat to be had from the three fallen men.

Packer confessed to taking the valuables of the deceased members, claiming they no longer needed them, but made no statements as to the exact items taken nor to the amount of money accrued.

While he was in jail, observers challenged his credibility and noted that Packer, far from being a victim of cold or starvation, had probably set a trap and led his group in the middle of the hills to kill and rob them.

They lay above the Lake Fork of the Gunnison River, now known colloquially as Dead Man's Gulch, which matched the description of where Packer had originally claimed that only Bell was killed.

The local coroner and law enforcement set out for the site along with about 20 volunteers and discovered the bodies of all five men in various states of decomposition, having been left to the elements and animals for four months.

Shannon Bell lay with largely skeletal legs splayed and arms to his sides that were crudely cut to their bones leading to hands that were still fully skinned.

The theory at the time was that Packer killed the men before supplies ran out to rob them of their possessions, got snowed in, and then lived in his makeshift shelter for months, walking to his slain companions and slicing meat off as needed.

Months had passed with no definitive evidence of a crime having been committed, no bodies discovered, and no formal charges lodged against Packer — other than the attempt on Lauter's life, which was not tenaciously sought for prosecution and used more as a means to keep him under custody.

People at that time were well-acquainted with the story of the ill-fated Donner Party, who had resorted to cannibalism during the winter of 1846–1847, and were understanding to a degree of the dire need to eat in the unforgiving wilderness.

[16][17] On March 11, 1883, Packer was discovered by Jean "Frenchy" Cabazon in Cheyenne, Wyoming, living under the alias of "John Schwartze", one of the original members of the Utah mining party who stayed in Chief Ouray's camp in the winter of 1874.

It was the argument of the prosecution that the only logical reason for Packer to have attempted such a perilous journey through the mountains with such minimal food and supplies was for the sole purpose to lead the men into the wilderness to both kill and rob them.

Further emphasis was placed on the fact that Packer's choice to hike through the San Juan Mountains during the middle of winter, where snow depths can exceed more than six feet in a single downfall, coupled with blistering winds and freezing temperatures, was practically suicidal.

Nevertheless, he was paroled on February 8, 1901, following a campaign that was initially spearheaded by an old acquaintance of Packer's named Duane Hatch, who petitioned for his release for nearly a decade before his labors came to the attention of Polly Pry.

Her stories on Packer led to a change of heart within the local businesses and people such that a series of petitions and requests made their way to the office of Colorado Governor Charles Thomas, which were still met with strong opposition.

[citation needed] Packer is today widely rumored to have become a vegetarian before his death and was reported by those who knew him as a man rich with stories and well-liked by children.

On July 17, 1989, 115 years after Packer consumed his companions, an exhumation of the five bodies was undertaken by James E. Starrs, then a professor of law specializing in forensic science at George Washington University, following an exhaustive search for the precise location of the remains around the area of Cannibal Plateau.

The three other skeletons showed defensive signs of hacking marks across the radial and ulna bones of their forearms (Shannon Bell being one), which one could sustain whilst shielding his face and body from an attack.

In 1994, David P. Bailey, Curator of History at the Museum of Western Colorado, undertook an investigation to turn up more conclusive results than Starrs' with respect to Packer's claims of having shot Bell.

Exhaustive investigation into the pistol's background turned up documents from the time of the trial: "A Civil War veteran that visited the crime scene stated that Shannon Bell had been shot twice and the other victims were killed with a hatchet.