He had already robbed her, raped her, shot her in the head, then forced her into her kitchen where he grabbed a butcher knife from a drawer. "I started to scream," the woman said later, and as she screamed the man fired at her from a distance of two feet. The bullet ricocheted off her front tooth. With the butcher knife, he slashed her neck and hands and then ran off.

"I had no particular reason," said her assailant, William E. (Tommy Thomas, 18, during an interview in his jail cell this week. "I don't know why. I still think about it. I wish it hadn't happened. It's too late to think about it now."

Thomas, his voice at times barely audible, said he was "shocked" when a D.C. Superior Court judge sentenced him last Friday to serve a minimum of 37 years in prison for the series of rapes, robberies and an assault he committed in the prosperous Kalorama Triangle area of Washington last fall. He seemed preoccupied with the fact that "I'll be 55 when I hit the streets again."

What emotion Thomas showed during the hour-long interview was confined to thoughts about his family for whom, he said, he stole. When asked about the women he raped, he shrugged his shoulders. He was indifferent.

"It was just there, you know. It was just something that happened," he said.

"As a kid I thought it was all a game," Thomas said. He began what turned into a life of crime by setting off false fire alarms when he was 7 years ago. Then it was truancy, house-breaking, burglary and robbery. By the time he was 16, there were 22 offenses listed on his juvenile record.

It was the pattern of a delinquent child who grew into a violent man.

Thomas was in and out of juvenile detention facilities. The product of a chaotic and abusive home, he spent a year, at the city's expense, at a private school for emotionally disturbed adolescents. By 1975, when Thomas said he decided he "couldn't beat the system," his behavior improved. He was placed in a halfway house. He had developed an interest in cooking and talked about joining the Marines. He was described then in case records as "a likeable, ambitious young man."

Then, in September, 1976, Thomas' childhood game erupted into a reign of terror for the people who lived in the Kalorama Triangle area. For two months, the government alleged, Thomas carried out a string of armed robberies armed rapes, assaults and other offenses in that neighborhood. The crimes were carefully calculated, the government said, and the work of a hardened, sophisticated criminal.

Victims and residents in and around the Kalorama area joined in an unusual effort to cooperate with the police, blanketing the neighborhoods with information about the man terrorizing them.

On Dec. 7, Thomas was arrested after a liquor store clerk recognized him from a police composite drawing. Four months later, he pleaded guilty to three charges of armed rape, five charges of armed robbery and one charge of assault with intent to kill.

Last Friday, Thomas sat in the D.C. Superior Court, about tot be sentenced. His attention was focused on his hands and he appeared not to listen as the woman he had robbed, raped, shot and stabbed told Judge Eugene N. Hamilton how she had been assaulted.

Because of his age, Thomas could have been sentenced under the Youth Corrections Act to serve an indeterminate term at the Lorton Youth Center. In a letter to Judge Hamilton, however, officials said that Thomas' "lengthy juvenile record, the scope and viciousness of the present offenses and an almost complete lack of remorse about them indicate a hardened, impulsive, unfeeling young man far beyond the Youth Center to assist."

"I guess they feel from my background they can't help me," said Thomas who said he "didn't figure" the Youth Center would turn him down.

Underneath his bland attitude are layers of repressed hostility and deep seated emotional sears, according to the reports of psychiatrists and psychologists who have interviewed Thomas.

Thomas was severely abused and neglected as a child. His feet were once set afire with lighter fluid after he came home late one night and tried to sneak into his house.

"The beatings were like stuff out of the slavery days," said Thomas, who said he was once whipped with an extension cord.

"I remember all of them, very well," he said.

"If you treat a human being the way he was treated, and you brutalize a child the way he was brutalized, this is what you get," said Judge Hamilton during an interview after he sentenced Thomas.

Now, Hamilton said, Thomas "is just like an animal, no sense of society . . . as a result of what he went through . . . and it was massive."

Thomas case file is thick with descriptions of the years he spent at various juvenile detention centers, starting in 1968 when he was 8 years old. Records describe him as a likeable, at time exceptionally bright child, who once scored unusually high on an intelligence test, who kept his cottage room neat and clean, who often adapted well to an institutional setting.

But he never stayed for long and his record is marked with escapes and new arrests. Te was anxious and aggressive and impulsive and confused about himself, the records said.

"I just don't like being in one place . . . being cooped up," said Thomas of the days he spent in those institutions, going to school, watching television, playing cards and pool.

In 1973, while Thomas was at Cedar Knoll in Laurel, the city's facility for delinquent youths, officials decided he "needs and deserves a special opportunity to develop emotionally and academically."

So, Thomas was sent to the Leary Educational Center in Cross Junction, Va., a private residential school that contracts with the District to provide special education for adolescents with emotional and behavioral problems.

Thomas performed well in the classroom and excelled at sports. But after a year, according to his records, he was sent back to Washington because officials at Leary said he was aggressive and showed "poor adjustment." He was accused of stealing and other offenses, according to the records.

He returned to Cedar Knoll. He escaped three times and committed two new offenses, both robberies. He was transfered to Oak Hill, another District facility for seriously delinquent youths. His behavior improved.

By then Thomas was 16 years old. He knew the prosecutor had the option to try him as an adult. Thomas knew, he said, "if I got caught I was going to do time" in a prison and not in a juvenile institution.

"His improvement has progressed tremendously . . . he's a very likeable and ambitious young man," officials wrote in October, 1975. On their recommendation, the following December, Thomas was sent to a halfway house on 13th Street NW. Adjustment was good, the records said, until April, 1976, when Thomas left the halfway house and never came back.

Thomas had returned home and juvenile officials made no attempt to pick him up after his mother indicated his adjustment was "excellent." He said he worked at a liquor store for a while, then quit. He had a job at a sandwich shop but was fired.

"I worked, I tried to be a good citizen." Thomas said, but he couldn't get another job.

"I went to hotels and signed applications and I went to restaurants and signed applications. Same old stuff. "Don't call us we'll call you."

Meanwhile, he said, he needed money. His family which is on public assistance needed money for food. His brothers needed clothes and shoes. In September, the robberies in Kalorama Triangle began.

"I try not to look back on it, the past is the past," Thomas said, "I try to look to the future, but my future holds nothing."

Judge Hamilton said when he determined the length of Thomas' prison sentence he relied on "a rule of thumb that people who have deep seated emotional problems as young adults cannot be cured until the age of 40 "when the amount and extent of their criminal involvement tapers off."

Hamilton recommended that the Bureau of Prisons commit Thomas to a federal institution where psychiatric care is available. "If he gets no help, then you've got the act working for you that he (will be) substantially past the age of 40" upon his first chance for release.

"I just don't think it's fair to ask society to take any more risks with this individual . . . he's done his share," Hamilton said.