Predators slipped back into the program by falsifying personal information or skirting the registration process. Others were able to jump from troop to troop around the country thanks to clerical errors, computer glitches or the Scouts' failure to check the blacklist.

In some cases, officials documented abuse but allowed the abuser to continue working with boys while on "probation." In at least 50 cases, the Boy Scouts expelled suspected abusers, only to discover later that they had re-entered the program and were accused of molesting again.

In the larger Baltimore region, cases were identified in Aberdeen, Bel Air, Cockeysville, Columbia, Essex, Glen Burnie, Lansdowne, Linthicum, Perry Hall, Perryville, Odenton, Riverdale, Waldorf and Westminster.

There is also a large cluster of cases in and around Washington.

Leaders of some local troops listed said efforts have expanded in recent years to make sure abuses are not repeated.

One of the most recent Maryland incidents listed in the database involved Boy Scout Troop 741 in St. Michaels in 2003.

Troop Leader Bill Roth, who started with the Talbot County troop after the alleged abuse occurred, said it involved a teenage Scout and a younger Scout.

The perpetrator of the alleged abuse was "one of the Boy Scouts themselves, not a leader," Roth said.

Roth said he does not know many of the details of the case. He knows the name of the alleged perpetrator, who was 16 or 17 at the time of the abuse, he said, but declined to give it to a reporter. He said he did not know whether the incident was reported to the police.

Like other troops, Troop 741 follows association guidelines for preventing abuse from happening, Roth said.

"All leaders that are involved with the boys have to have youth protection training, they have to fill out an application and go through background checks, and no one adult can be with one Scout alone at a time," Roth said. "It's called two-deep leadership."

That policy banning one-on-one contact was implemented in 1991, according to the Boy Scouts of America.

The policy requiring criminal background checks on professionals and staff of the organization who work with youth was established in 1994. Third-party, computerized background checks for all volunteers began in 2003.

Isolated activity between two Scouts is also generally prevented, especially between Scouts of different ages, Roth said.

Still, abuse remains a concern — just as it was years ago when he helped coach his son in youth sports, Roth said.

"It's a concern in everything you do nowadays, and I'm sure they didn't handle it properly back then," he said of abuse cases linked to the Boy Scouts from decades ago. "It's a shame it goes on. I don't know the answer."

In another recent case, involving Boy Scout Troop 447 in Linthicum in 2001, assistant Scoutmaster Matthew B. Showalter, then 24, was arrested after the mother of a Scout called the Department of Social Services and said her son told her he'd been inappropriately touched at a meeting.

According to a Baltimore Sun article from the time, the victim told police that on multiple occasions he'd been told to leave the area where the Scouts were meeting and go to an area away from everyone else, where had had to undress and was touched or spanked before he could return.

Showalter, of Glen Burnie, was charged with child abuse, sex offenses and assault. He was eventually found guilty on a single count of child abuse and sentenced to serve 11/2 years of a 10-year prison term, plus five years of supervised probation, according to court records.

John Murawski, the troop's current leader, said that like the St. Michaels troop, his troop operates under the "two-deep leadership" policy, never allowing a single adult to be alone with a single Scout.

Murawski, who said he has been the troop leader for the past three years, said he had heard about the previous abuse but didn't ask for details.

"I knew something had happened in 2001, or at least in the previous years, but what had happened, I didn't ask," he said. "As long as we're not having any issues now — that's my worry, to be honest with you."

Jason Felch and Kim Christensen are reporters for the Los Angeles Times. Kevin Rector is a reporter for The Baltimore Sun.