Arthur Johnson, now 63, was accused of taking part in two escape attempts during his early years in prison, the last time in 1984.
But lawyers trying to get him moved to the general prison population say the second claim of an escape attempt seems farfetched because he was already in solitary at the time. In any case, they say, he has had only three minor infractions in the past 25 years.
Bret Grote, an attorney at the Pittsburgh-based Abolitionist Law Center, which fights for prisoner rights, said the punishment amounts to torture. In a federal lawsuit, he argues it violates constitutional protections against cruel and unusual punishment.
It's "unthinkable, unimaginable," he told The Philadelphia Inquirer (http://bit.ly/1WN5ihF ).
Prison officials wouldn't discuss Johnson's case but said grounds for placement in solitary include a history of assaults inprison, sexual abuse and escape attempts.
Johnson wrote in a declaration that is part of his lawsuit that prison officials have not allowed him to work, take classes, or participate in prison activities for 36 years.
Solitary, he wrote, "has caused me to not feel emotions like I once did. I can no longer understand the feelings of others. I feel flat and depressed." His cell is "smaller than many cages used to hold animals at zoos," he wrote.
Johnson is now held at the State Correctional Institution in Frackville, about 100 miles northwest of Philadelphia. A teenager at the time of the crime, he was placed in what is officially known as "restricted housing" in 1979, when he was 27.
According to his lawsuit, he lives in a 7-by-12-foot space where the lights stay on day and night. He can't see or talk to other inmates. He leaves the cell only to shower, alone, three times a week, and for hour-long outdoor recreation in a caged area about the size of his cell five days a week.
There is only one other Pennsylvania inmate in solitary longer than Johnson: An inmate who killed a guard has been in restricted housing since 1973.
Johnson got involved in a fatal gang fight in 1970. An accomplice who passed a polygraph test blamed Johnson, who court records show confessed, was tried and was sentenced to life in prison without parole. He later claimed police beat him and that the confession should not have been admitted because he was classified as "educable mentally retarded," but his appeal failed.
His lawyers said he became a target for "severe state repression" when he began associating with imprisoned members of the black liberation movement in the 1970s.
He has been moved around nearly a dozen state prisons since 1979, but always in solitary, except for six months in 1989-90, when he was housed in federal custody for space reasons, the Inquirer reported.
His lawyers speculate that institutional inertia may play a role in why Johnson is still stuck in solitary.
"This person has been locked down for so long, that sends the message to the guards, to those who run the institution ... that this is where Mr. Johnson belongs," Grote said.