Francis Harper, a convicted armed robber, decided to teach a lesson to the inmate who switched the television channel in the county jail. Harper decided to rape him.

"I felt threatened," said Harper. "I felt like he was trying to take over the cell block and change things."

Harper, now 21, has mastered the violent art of surviving in the Prince George's County Detention Center, where rape is common among heterosexual men because it is the best way for an inmate to command fear and respect among other inmates.

Now serving time in the Patuxent Institution in Jessup, Harper spoke openly about his experiences as a jail rapist at the detention center. He says he raped three men in the county jail during 1978. He was convicted of one of the rapes -- the only rape case in the county jail that has been prosecuted during the past four years. The other two rapes were not reported to jail officials.

"The basic thing was to keep fear in the air to keep that respect," Harper said. "I was aggressive because I was afraid. I took the fear I had and reversed it. I was afraid of getting killed . . . . I was on edge all the time. I used to think: Maybe tomorrow I'll get killed, or tomorrow I'll have to kill."

Harper, who is short and thin, says he was not motivated to rape because of sexual desire. "If you really want to get a guy, you take his manhood," Harper said. "It's a scar that will always be with him. Something worse than murder."

Harper grew up in a dilapidated house in Capitol Heights, the fifth of nine children. At home, Harper felt that he was a victim; he says he received occasional beatings.

Before long, Harper became the aggressor. When he was 13, he began robbing stores and supermarkets in order to prove himself and bring home steaks and furniture for his parents. "I knew they wanted those things," he said in an interview. "I was trying to get closer to them."

For several years, he went in and out of detention homes for juveniles.

Then, at age 17, he was locked up in the county jail on an armed robbery charge. He began to feel insecure because he did not feel the guards would protect him from other inmates.

His belief was based on certain observations. He was in a small, crowded cell block in the "upper right" section of the jail with 10 men who were charged with or convicted of armed robbery or murder. The men, who were tense and angry about being in jail, frequently got into fights or threatened each other with rape. A guard was rarely present. On the night in 1978 that Harper raped the man who switched the television channel, for example, a guard visited the cell block at 11 p.m. to count the prisoners; then he left and did not return until seven hours later, according to court documents.

"I was afraid of trusting in the jail," said Harper. "I figured it was everyone for themselves -- a continuation of life on the street. I felt like I needed control and had to take everything I wanted."

Harper said he tried to show that he was not someone to be trifled with. He beat up someone who tried to steal his toothbrush. He refused to give anyone cigarettes. And he never stepped aside for anyone.

He added to his tough image by not making phone calls. He turned down visits from his parents and his girlfriend. He did not write letters to anyone.

"A guy with hope of getting out of jail is weak," says Harper. "I always presented the image that I didn't want anything to do with the outside world. That used to scare a lot of guys."

After he instilled fear in the others, Harper became the leader of the cell block. He decided when it was time to sleep and time to listen to the radio. He chose the television programs. He decided who could use the telephone and for how long.

Then a new inmate, a 24-year-old plumber from Suitland, entered the cell block. From the start, Harper felt threatened by him. The plumber, who asked not to be identified, never had been in jail before; he was short and thin and, like Harper, was scared for his own safety. So the plumber tried to gain his own following among the inmates, much like Harper had done previously.

"He used to walk around like he was rough," says Harper. "He used to try to influence other guys whom we had in check."

Harper began worrying that he would lose control of the cell block--and perhaps lose his life. He decided that he had to challenge the plumber. "Either you bite," says Harper, "or you get bit."

The opportunity came when the plumber changed the channel of the television in the common area of the cell block, an act Harper interpreted as disrespect.

For a period of three hours, Harper and another inmate, David Lamont Rowe, beat the plumber. They also raped him and tortured him, shoving a toilet bowl brush and a toothbrush into his rectum, according to Harper and a statement that a witness, Clifford Hendricks, gave to police.

"I could hear the inmate yelping in pain," Hendricks told police. Hendricks had been trying to watch television in the dayroom next to the plumber's cell.

Hours later, when the guard finally passed by at 6 a.m., the plumber told the guard that he wanted to see a doctor. He was taken to Prince George's General Hospital, where he was treated for numerous bruises on his chest, back, arms and legs, and "tenderness" of his rib cage. In addition, according to medical records, there were injuries to the victim's anus and doctors confirmed that he had been raped. Pain kept the plumber from sleeping for weeks, he said in an interview.

The plumber also suffered emotionally. For two years, he was afraid to be near any group of men. As a result, when he was transferred from the jail in Upper Marlboro to a prison in Maryland to serve out his sentence, he asked to be put in "protective custody," a term for staying in a cell by himself for 23 hours and 45 minutes each day. His only recreation consisted of one 15-minute walk per day and two showers per week.

When he went before the parole board last year, he was denied parole and was told that he would not be reconsidered for parole for another two years. One of the reasons, according to Greer Bosworth of the Maryland Parole Commission, was that he had not engaged in any programs, such as school classes, because he was in protective custody.

Unlike most jail rape victims, the plumber filed a civil suit against the county jail for physical injuries and mental anguish. The $1 million suit, which was filed last year in federal court in Baltimore, was settled by the county for $12,000.

Meanwhile, Harper's status rose, he said. "The other inmates looked at me as a god," Harper said. "They'd say, 'I heard what you done.' "

Suddenly, everyone wanted to be his friend, he said. Inmates would ask him if he wanted to take their turn at the phone, or if he wanted their dinners or their toothpaste. Some offered him their sisters' telephone numbers.

Some were generous because they wanted to use his name as a sort of shield, a way of protecting themselves from other inmates. "Be cool, I know Harper," they'd say. Others felt that Harper would not take advantage of them if they gave him things--and on occasion they were right.

Why did the rape become a gang rape? "Because everyone's as scared as the next person," said Harper. "I'd say, 'We're going over here to try this guy, you going with me?' If they say no, I'd say, 'You a punk or something?' The guy will say he's not a punk, so he has to come along because it helps him to avoid it happening to him. He knows you're looking for a victim and he doesn't want it to be him."

Harper claims that the rape was particularly brutal because he and Rowe and the others "got into a competitive thing. Everyone was tryng to prove how bad he was to everyone else."

Looking back on the rape, Harper believes that he was motivated not only by fear for his safety, but also by feelings of anger and frustration over being in jail. And the poor conditions of the Upper Marlboro jail -- including extreme overcrowding, toilets that are frequently stopped up and recreation often limited to one hour of gym a week -- made those feelings even more intense, according to Harper.

"When they cage a person, it makes a person real bitter and angry; you don't know who you're angry at," said Harper. "So you have these feelings and you take them out on somebody else.

"I feel they create monsters in jail. People on the outside say we don't care about jail conditions; eventually these same people inmates who are subjected to this treatment are turned loose again; they're mad and they terrorize everyone."

Harper says he has changed since being incarcerated at Patuxent, an unusual prison where rehabilitation is emphasized, where there are many guards, where living conditions are better, and where he sees psychiatrists and social workers several times a week.

"I feel a lot of remorse about it," he says, referring to the rape. "I wasn't strong enough to withstand the influence of my environment. They helped me be an animal in that jail and I submitted to it."