but that didn't bother his new prison friend.

It also didn't worry the man's mother, who was confident her son would be safe in the state's most secure prison.

Now authorities say Gleason's new prison buddy is his latest victim, and the inmate's mother is questioning why prison officials didn't take Gleason's threat to kill again seriously.

So is Gleason.

"Now why did they put me outside with other inmates after I killed an inmate and I said what I said about if I don't get the death penalty," Gleason wrote to The Associated Press days after Cooper was killed on July 28. "This place doesn't make sense."

Gleason said he told investigators he killed 26-year-old Aaron Cooper because his prison lawyer told him he would not get the death penalty when he's sentenced later this month. He said he also was frustrated that he had submitted motions and subpoenas to the court that had not been addressed.

Gleason signed the letter "The New and Improved Boston Strangler."

"You knew this man threatened to kill, and you gave him the opportunity to kill my son," Kim Strickland said in an interview days after Cooper was killed.

Cooper told his mother he and Gleason talked about God and other things to pass the time in the segregation unit at Red Onion State Prison, a supermax prison in the mountains of southwest Virginia. Gleason gave him stamps and paper to write home, and Gleason even wrote to Strickland asking her to be his pen pal.

"I don't want you thinking that I'm talking with a Satan worshipper or the boogeyman," Cooper wrote to his mother on June 24. "He's just another guy locked up."

Just over a month later, prosecutors say Gleason lured Cooper to the chain-link fence dividing their cages in the recreation yard saying he had a gift: a gang necklace. Instead, it was a noose fashioned from torn bed sheets that he used to strangle Cooper, Wise County Commonwealth's Attorney Ron Elkins said.

Gleason, 40, is scheduled to be sentenced Aug. 31 for killing another cellmate, Harvey Watson Jr., last year. At the time, Gleason was already serving a life sentence for killing a man in 2007. Elkins said he likely would wait until after the sentencing later this month to charge Gleason with Cooper's death.

Strickland, like some of Watson's family members, said she does not want Gleason to get the death penalty — not out of mercy, but because being executed is what he wants.

"If he wanted to die, why didn't he commit suicide?" said Strickland.

"They're going to have to make new provisions to keep that man, but he should rot in prison, die in prison."

Strickland questions why guards didn't stop her son's death. Prisoners in segregation at Red Onion are isolated except for one hour a day, when they are placed in separate outdoor cages for recreation.

Elkins said a seemingly unsuspecting Cooper helped Gleason slip the end of the noose through the fence and place it across his neck. Elkins said guards noticed Cooper was dead when they came to return Gleason to his cell.

Gleason said Cooper was dead for about 45 minutes before corrections officers found him. He also said strip searches that usually are conducted before inmates go to recreation were not done that day.

Prison officials refused to comment on the death or to discuss how many guards were watching Gleason, Cooper and three other inmates who were at recreation when Cooper was killed, citing the ongoing investigation and safety concerns.

In the previous case, Gleason fired his attorneys and pleaded guilty to killing Watson days before his June 1 trial. He told prosecutors he would kill again if they didn't seek the death penalty in his case.

"I murdered that man cold-bloodedly. I planned it, and I'm gonna do it again," Gleason told The Associated Press in May. "Someone needs to stop it. The only way to stop me is put me on death row."

Gleason said he begged correctional officers to move Watson, who suffered from mental illness and sang, screamed profanities and masturbated in the 8-by-10-foot cell they shared at Wallens Ridge State Prison for seven days in May 2009.

On the eighth day, correctional officers found Watson bound, gagged, beaten and strangled. His death went unnoticed for 15 hours because correctional officers had not followed proper procedure for inmate head counts at the high-security prison.

Gleason was moved to Red Onion after Watson's death. He remains there in segregation.

Cooper's mother said he suffered from bipolar disorder and Attention Deficit Hyperactivity Disorder. He was serving 34 years for a string of robberies and carjackings. He was sent to Red Onion after starting a fire at another prison.

Cooper spent much of his childhood in and out of psychiatric facilities while Strickland, a single mother who worked as a barber, struggled to make ends meet. Cooper joined the Crips street gang and was locked up not long after his 21st birthday.

Strickland said she was shocked when she found out Gleason was involved in her son's death less than a month after writing to her. She had written him back, asking about his past.

"First of all, I'm not looking for a sugar mama. I have my own money," Gleason wrote to Strickland on June 30. "I'm just looking to write someone because after I got my time I cut everyone off because I put them threw (sic) enough."

Strickland said she would like to visit Gleason in prison so she can ask him why he targeted her son. She also wants answers from corrections officials, who have told her they can't answer her questions because of the ongoing investigation.

"I promised my son when I saw him (to identify his body), if it's the last breath in my body, whoever did this and allowed it to happen, I would see them brought to justice," she said.