The burly, six-foot-tall corrections officer curled up the right corner of his mouth and gave the McKinley High School students a cold stare with his steely gray eyes. "This isn't a fun place," he said soberly. "That's all I can say."

With that, the students were led into the drab visiting room at Lorton Reformatory to meet inmate Sidney Davis, who wore sweatshirt, jeans and pale blue beach cap -- not unlike the clothes the students wore. Davis' face was lean and scarred. "I've been here 12 years. My charge is murder. I'm doing 20 years to life," he told the students. Some of them gasped.

It was the first time most of these 22 D.C. students had ever been inside the prison, and they walked outside its high fences at the end of their tour saying they never wanted to return. That is just the effect school officials say they are after. For the past few months, the schools' security division has been taking groups of students from various schools to Lorton in an attempt to reduce violence and vandalism and prevent students from taking drugs and embarking on a career of crime.

It was McKinley High's turn to go yesterday. The Northeast school, though one of the better academic schools in the city, has been the site of two shootings in the past three years. About half the students who went on the tour yesterday volunteered.

Most of the students were impressed with how articulate the inmates were, though a few students walked away saying they had learned nothing they "didn't already know."

What seemed to have the most impact on the students was the personal testimony of the inmates -- most of them young men in their 20s, in sneakers and jeans, who told the students they too had been D.C. public school students just a short while ago.

McKinley senior Samuel Stills said he was amazed at "the way they said they couldn't do the things they want. Somebody is always watching them." He glanced at one of the high brick towers from which armed guards survey the grassy, 70-acre facility. "At least I can go home to my room, watch my television, listen to my radio, do anything I want. They can't do that," Stills said.

Stills had just heard an inmate tell of how he had attended his father's funeral in handcuffs, accompanied by two prison guards.

"For me it was like a fantasy world. It doesn't seem like reality that those things could happen to them," said Rosita Washington, a 10th grader, referring to the story inmate Davis had told about how he was stabbed in the back and in the head by fellow prisoners in a fight over drugs.

"Some of them said they have double life sentences . A person only has one life!" Washington said, shaking her head.

When the inmates showed slides of the arms of heroin addicts, swollen and deformed and covered with sores, Washington and another girl began to cry.

"I had never seen anything like that," Washington said.

Most of the inmates who talked with the students said their problems started with drugs. "I want you to know about the genocide that has taken hold of the black community . . . and it's drugs that are taking so many of our young people down the drain. Drugs and alcohol, another destroyer," said inmate Dexter Forbes, 28, a former Eastern High School student. Forbes is serving a 30-year sentence for armed robbery.

"I was at Cooke Elementary when I smoked my first stick of marijuana," said Michael Mose-el, 27, an armed robber serving a 30-year sentence. "I started shooting heroin when I was 13 years old. I shot drugs until I was 20 and arrested. Now my main concern is my family. I'm married. I have three children, and there's very little I can do for them in here."

Though the inmates said they had started out using and dealing in drugs like marijuana, some of the McKinley students said they still feel that marijuana is basically harmless.

"They probably used heroin or something like that. They used them heavy drugs and that influenced them to commit crimes," said 11th grader David Rush. "Marijuana only affects people who have weak minds."

Inmate Ricardo Eley, 21, serving a life sentence for murder, warned that he too ignored admonitions about drug abuse when he was a student at Roosevelt High School in Northwest. Eley, who coauthored the slide show on drug use with inmate Joseph Sweat, said he was offered scholarships to four different colleges, "but I never got the opportunity to use any of them because I came this way . . . ."

"It's very hard to get this point across, but I'm a living example of a black dude who got involved in drugs."