Just weeks ago, they were troublemakers, working their way through the criminal justice system, convicted of crimes from drug dealing to manslaughter. Today, they stand at attention, heads shaved, eyes straight ahead. Every phrase ends with an emphatic ``Sir!'' Every item in their foot lockers perfectly folded, every order perfectly obeyed. No, they haven't joined the military. Not exactly. They're probationers at Camp Sauble, Michigan's 5-month-old experimental ``boot camp'' prison, where ``shock incarceration'' is used to jolt 17- to 25-year-old offenders into straightening out their lives. On Monday, reporters got their first glimpse of the intense physical training and military-style discipline the probationers endure for 90 days. From the first day, the offender is ``told he's an embarrassment to society, ... a parasite to society,'' said Inspector Bruce L. Curtis, an ex-Marine drill instructor. ``We start working on their minds,'' Curtis said. ``It's the first time they've ever been held accountable for anything. Instead of holding down a job or going to school, it's been easier for them to knock some old lady on the street and take her Social Security check.'' At first, 19-year-old Jesse Roberson of Pontiac didn't think he could make it through the program. ``When I first came here I was pretty scared,'' said Roberson, who was driving drunk when a passenger in his car was killed in a crash. He faced 15 to 30 years in prison for manslaughter. Roberson's now looking at graduation in two weeks. ``You come in a baby and you leave a man,'' he said. ``This program got rid of my temper and makes me want to go out and do something positive with my life.'' Scott Fetzlaff, 20, of Manistee, said he's had time to think about his mistakes, including his breaking and entering conviction. ``They scare everything right out of you the first day,'' he said. ``It's going to change my ways when I get out.'' The program, which began March 1 at a former minimum-security work camp in the Manistee National Forest, has had seven graduates and now has 70 probationers, about half its capacity. Two men escaped, only to be captured within 24 hours, and 16 others have flunked out, returning to the judge for resentencing, usually resulting in a multiyear prison term. Those who disobey orders may be required to carry a 25-pound ``motivational'' log on their shoulder for the day, or to perform ``motivational'' detail, possibly digging out a tree stump by hand. For the probationers, days begin at 5 a.m. with the screams of a corrections officer or the banging of trash can lids at their heads. Physical training, cleaning buildings and 7{ hours of chopping trees in county, state and federal parks make up most of the 17-hour days, followed by educational and substance abuse programs at night. One hour of free time may be spent watching television news or writing letters. No visits are allowed, and one 10-minute telephone call may be made each week after the first six weeks. The men march double time, chanting in unison after the officer in charge, ``Mental tough, mental hard! I can do it! You can do it! We can do it!'' A shifting eye while standing at attention may result in 15 push-ups on the spot. There is silence at meal time. The program is modeled after similar programs in other parts of the country, but is designed for more ``hard-core'' offenders than the others, said Donald Hengesh, state Department of Corrections project coordinator. While offenders must not have served any previous prison sentence, their convictions range from felonious assault and manslaughter to forgery and narcotics possession. ``There are no Sunday school cases here,'' said Hengesh. The Department of Corrections has notified judges and probation officers that the program is an option for offenders who, according to sentencing guidelines, would face at least one year of prison. The only exception would be a probation violator with a new felony conviction, who might be sentenced to a prison term of less than 12 months. Candidates must never have served any prison time and must be physically able to participate. Offenders convicted of sex or arson charges also are not admitted. The program is proving cost effective, with each inmate costing $3,846, compared with $20,000 each state prison inmate costs annually, Hengesh said. While civil rights activists argue intimidation and fear don't rehabilitate, state Sen. Jack Welborn, who sponsored legislation to fund the camp, said he's sold on the program. ``I believe a kid in this program has a better chance of going straight when he gets out than in any other program in the corrections system,'' he said. ``The kid that goes into prison comes out a better criminal.''