(CNN) -- One of the men found guilty of murdering Ahmaud Arbery fears being killed in state prison and wants to remain in federal custody for his safety, according to a court document filed by his attorney.
Travis McMichael, along with his father Greg, and their neighbor, William "Roddie" Bryan, was found guilty in the February 2020 shooting death of Arbery in the Satilla Shores neighborhood of Brunswick in Glynn County, Georgia.
They were convicted in November 2021 on the state murder charges. The McMichaels were sentenced to life in prison without the possibility of parole. Bryan received a life sentence with the possibility of parole.
In February, a jury found the three guilty of all charges in their separate federal hate crimes trial, backing prosecutors' case that the White men chased the 25-year-old through the streets of a Georgia neighborhood because he was Black.
Sentence hearings for the three are due to begin on Monday at the federal courthouse in Brunswick.
Travis McMichael's attorney Amy Lee Copeland filed a memorandum Thursday in federal court asking for her client to remain in the physical custody of the federal government because he is afraid he'll be killed once in the Georgia state prison system.
McMichael has been held at the Glynn County Detention Center since his state arrest in May 2020, according to the memo, and has received threats that people "are 'waiting for him,' that he should not go into the yard, and that correctional officers have promised a willingness (whether for pay or for free) to keep certain doors unlocked and backs turned to allow inmates to harm him."
"His concern is that he will promptly be killed upon delivery to the state prison system for service of that sentence: He has received numerous threats of death that are credible in light of all circumstances, and the government has a pending investigation into the Georgia DOC's ability to keep inmates safe in a system where murder rates have tripled," the memo said.
It said McMichael had received hundreds of threats and "quit counting in January 2022, at around 800 threats."
Along with safety concerns, the memo also cites "the government's investigation into the violence in Georgia state prisons," as reasons that McMichael should remain in the physical custody of the federal government.
CNN has reached out to McMichael's attorney for comment.
Arbery's family has objected to the killers serving time in federal instead of state prison.
In January, a federal judge rejected a plea deal reached by prosecutors and Travis McMichael on the hate crime charges.
McMichael had agreed to plead guilty to a single hate crime charge -- interference with rights -- in exchange for prosecutors recommending he serve 30 years in federal prison.
Arbery's mother, Wanda Cooper-Jones had urged the judge not to accept the plea.
"Granting these men their preferred conditions of confinement would defeat me. It gives them one last chance to spit in my face after murdering my son," Cooper-Jones told the judge.
S. Lee Merritt, an attorney for Arbery's mother, had previously called federal prison "a country club compared to state prison," saying the facilities were less populated, had better funding and were "generally more accommodating" than state holding facilities, according to tweets from his account.