David MacDonald Rankin, a former College Park Boy Scout leader, was sentenced yesterday to 15 years in prison for what a Prince George's Circuit Court judge called the "absolutely incredible" crime of having members of his troop perform sex acts with him.

Rankin, 28, had pleaded guilty to 11 counts of child abuse, all of the charges stemming from his involvement with nine scouts whom Rankin had put through an initiation ceremony into a special group within his troop called "the Rowdies."

Reading from a prepared statement, Rankin asked Judge G.R. Hovey Johnson to sentence him to a long probation with community service. "I never intended to harm anyone," Rankin said. "They were like sons and little brothers to me. If I could turn back the hands of time, I would."

But Johnson, himself a former Boy Scout, said probation would be inappropriate in the case and sentenced Rankin to 15 years for each of the 11 counts, with the sentences to run concurrently for a total prison term of 15 years.

"I honestly find this troubling case to be overwhelming," Johnson said, "and I find the offenses that were committed with these young boys absolutely incredible.

"It cries out for punishment," the judge continued. "It cries out for deterrence."

The case against Rankin, an Eagle Scout and an honorably discharged Marine, spurred the National Capital Area Council Boy Scouts of America to come up with a new plan to help prevent child abuse in scout units.

The Boy Scouts of America had already maintained a computerized reference system that lists more than 2,000 former Boy Scout leaders who have had problems ranging from alcoholism to inability to manage funds, but not all names make it into the system.

The plan, released Dec. 15, did not call for any new screening of Boy Scout volunteers. Instead, it emphasized adherence to the Scout Oath -- "to keep myself physically strong, mentally awake and morally straight" -- and self-monitoring of behavior by scout leaders.

Rankin was arrested May 11, after the father of one of the victims notified officials of the National Capital Area Council.

About six months before that, said Assistant State's Attorney Thomas McManus, the father arrived earlier than planned to pick up his son from a scout meeting and thought he saw Rankin playing with his son's genital area. The father waited before notifying officials, McManus said, because his son denied for several months that anything had happened.

Rankin had led Troop 740 for five years before his arrest last spring. Eight of the incidents occurred with scouts ages 14 to 16 during the weekly troop meetings at a hall adjacent to Holy Redeemer Catholic Church in College Park. Three other incidents occurred at an overnight camping trip with the troop in Charles County. All of them happened between early 1985 and February 1987.

Rankin "had a clear sense from the beginning that what he was doing was wrong," McManus said.

"Some of the victims can talk about it with openness and candidness," McManus said. "They don't appear to be emotionally scarred, at least not on the surface. But others among the victims will be scarred for the rest of their lives."

A psychiatrist and a psychologist who have been counseling and treating Rankin since last summer concluded that Rankin suffered from a poor self-image and became involved in scouting "where he would be accepted and could excel," said Joseph DePaul, Rankin's attorney. The crimes were committed, according to DePaul's reading of the health professionals' evaluation of Rankin, to bolster his self-esteem.

Judge Johnson said that Rankin violated the trust parents have in organizations such as the Boy Scouts to help shape their children.

"I can recall personally the influences that the scoutmaster had on me," he said. "To have that trust violated to the extent that you violated it cannot be condoned, cannot be explained away by a sense of low self-esteem."