The evidence, which was never before seen to the public, includes 11 drawings some believe to represent the 11 people Keys is convicted of killing. "He drew a series of 11 skulls," Special Agent Jolene Goeden said. "These skulls are drawn in blood and these were found underneath his bed in his jail cell. And one of them says, ‘We are one.’... We believe that 11 is the total number of victims."
Keyes said he chose his victims at random.
"It was very disturbing, but also very saddening to know that that many people were victims to his crimes," Special Agent Katherine Nelson said. "I think he took pleasure in doing it."
Keyes secretly painted the skulls in his jail cell. They were discovered before he took his own life in the cell in December 2012. Not all of his victims have been properly identified.
"All the victims that we don't have identified: That's what this case is all about," Goeden said.
The FBI believes Keyes' murderous rampage stretched across America, from Vermont to Alaska, likely between 2001 and 2012. The FBI says that Keyes was one of the most careful and meticulous killers in American history.
Keyes studied the methods of infamous predators as well as the men and women who caught them, reading books the FBI’s top profilers wrote on their years of experience hunting monsters. He also drew from pop culture.
“He learned from 'CSI.' … He learned from 'Criminal Minds' how the bureau thinks. So he devised this way of being sure not to leave any DNA behind,” investigative journalist Maureen Callahan told InsideEdition.com in 2019.
His acquired knowledge was coupled with a unique upbringing and skills learned because of it. One of 10 children in a family brought up by survivalist parents,
Keyes spent his early years living off the land and honing his skills as a hunter.
“His parents pull the family up to a very remote area of Washington state when he's very young, when he's 4, to Colville, Washington, where the father spends seven years building them a cabin to live in. In the meantime, the children are living in tents,” Callahan said. “They have to hunt their own food so they can eat. So, you're building a child who's learning how to do all of this stuff while inculcating them with, ‘Don't trust the federal government.’”
But Keyes went on to become part of the federal government himself when in 1998, he joined the U.S. Army.
“From what men who served with him told the FBI, it was very clear that he was a super soldier and that the feats that he could physically perform were astonishing to them," Callahan said.
Investigators would come to learn all of this and more as they sought to glean more information from Keyes himself, but it wasn’t without struggle. Though he eventually admitted to killing Koenig and directed authorities to fher body, getting Keyes to divulge further information was extremely difficult.
His key motivators appeared to be keeping his name out of the media to save his daughter the anguish of having to read about her father, as well as the desire to expedite proceedings so that he could be executed for his crimes.
With the public's help, the FBI hopes to one day attach a name to each of the skulls that Keyes painted. If you have any information that be of interest to authorities, please call the FBI at 1-800-CALL-FBI, or report tips online.
"Tracking the Murders of Israel Keyes," an all-new "48 Hours," airs Saturday, May 9 at 10/9c on CBS.