ANCHORAGE — A man who confessed to killing an Alaska barista and multiple other people across the country died in his jail cell after slashing one of his wrists and using bedding material to strangle himself, Alaska State Troopers said Wednesday.

The state medical examiner hasn’t determined which of the injuries was the primary cause of Israel Keyes’ death.

Keyes, who was found dead in his Anchorage cell Sunday morning, had cut his left wrist with a blade from a disposable razor that was imbedded in a pencil. He also used a rolled-up sheet to strangle himself, troopers spokeswoman Beth Ipsen said.

“It was not a hanging,” she said. There was no sign that anyone else was involved in the Anchorage man’s death.

Crumpled, blood-soaked papers that appeared to have writing on them also were found in Keyes’ cell, and have been turned over to the FBI. Eric Gonzalez, an FBI spokesman, said the papers have been sent to the agency’s lab at Quantico, Va., for analysis.

The writing on the papers was illegible because of the blood, according to Ipsen, who said a pen or pencil was used.

Kaci Schroeder with the state Department of Corrections declined to say whether Keyes was allowed to have a disposable razor, or how he might have obtained one, noting the death was under investigation by her agency. Schroeder did say Keyes had been segregated from other inmates but was not on a suicide watch.

Keyes was awaiting a March trial in the death of Samantha Koenig, 18.

Authorities say he abducted Koenig in February from the Anchorage coffee stand where she worked, then sexually assaulted and strangled her. Keyes then left Koenig’s body in a shed outside his house while he went on a cruise. He dismembered the body when he returned two weeks later, authorities said.

Those details and others released Tuesday by the FBI provided the most comprehensive account yet of Koenig’s death at the hands of a man who confessed to the slaying and told authorities he had killed at least seven other people in the past decade.

The FBI said in a statement that it released the information “both to fully explain the courage and resolve Samantha displayed in the final hours of her life, as well as in the hopes that the release of additional details will help investigations of other murders committed by Israel Keyes.”

Gonzalez said Wednesday that tips were coming in from around the country about possible victims and Keyes sightings.

Once home from his cruise, Keyes tied up Koenig and posed her body to make it look like she was still alive. He then took a Polaroid of her with a newspaper dated Feb. 13 — 12 days after her abduction, according to the FBI.

Keyes made a photocopy of the picture and typed a ransom note on the back demanding $30,000 from Koenig’s family. He then sent a text message to Koenig’s boyfriend on her cellphone with directions to where he’d left the note at a local dog park.

Keyes, 34, disposed of Koenig’s remains in a frozen lake north of Anchorage after he cut a hole in the ice with a chain saw, authorities said.

He was arrested in March in Texas, after using Koenig’s stolen debit card at ATMs there and in Alaska, Arizona and New Mexico. He was facing a March trial in Koenig’s death.

After his arrest, Keyes confessed to killing Koenig and at least seven others. His other known victims were Bill and Lorraine Currier of Essex, Vt., who disappeared in June 2011. Keyes told authorities he also sexually assaulted and strangled Lorraine Currier. The couple’s bodies have not been found.

Koenig’s body was recovered from the lake in April after Keyes told authorities of its location.

Keyes didn’t identify his other victims or say where their remains were, other than to say four were killed in Washington state and one was killed on the East Coast, with the body disposed of in New York.

Keyes had lived in Washington state and had property in upstate New York. He traveled extensively in the U.S., landing at one location and targeting victims randomly hundreds of miles away, investigators said. He had never seen Koenig before, but chose the coffee stand because of its location and because it stayed open later than other stands.

Keyes told authorities he robbed several banks and used money he made as a general contractor to pay for his travels.