A man accused of killing five people at a Washington state mall last year was found dead in his jail cell Sunday.Arcan Cetin, 20, appeared to have hanged himself at the Snohomish County Jail, Skagit County prosecutor Rosemary Kaholokula told NPR.Cetin allegedly carried a Ruger rifle into a Macy's in the Cascade Mall in Burlington, Wash., on Sept. 23, 2016, and opened fire. A teenage girl, a man and three women died. Cetin fled and was caught the next day near his apartment. He was charged with five counts of first-degree murder.According to court documents, Cetin confessed to the crimes, telling detectives "he did bring the rifle into Macy's and shot all 5 victims," although he did not say why.Kaholokula told NPR that Cetin had not yet entered a plea in the case and he was awaiting an evaluation on whether he was competent to stand trial. A court hearing was scheduled for next week.Cetin was a Turkish-born, legal U.S. resident. Even before last year's mall shooting, about 65 miles north of Seattle, he was known to law enforcement. The Seattle Times reports Cetin's criminal record included three domestic-violence assault charges and that a judge had told him he was not to possess a firearm.Cetin had recently been transferred to the Snohomish County Jail from Skagit County Corrections at the request of his public defenders. The Times reports that he had talked to fellow inmates about his case, potentially setting them up to be used as witnesses against him during trial.The Snohomish County Sheriff's Office released a tweet confirming the jailhouse death, but did not identify Cetin by name.The family of one of the victims, Chuck Eagan, released a statement through the Skagit County Prosector's Office expressing shock over Cetin's death: