When an on-duty police officer was shot and killed by a colleague a month ago, residents of [Santa Maria, CA, an] agricultural community north of Santa Barbara were horrified. Outrage grew when they learned the shooting occurred as fellow officers tried to arrest the policeman on suspicion he was having a sexual relationship with a 17-year-old girl in the city's Police Explorers" program. But inappropriate relationships between officers and youths in the junior police program aren't all that rare. No organization keeps statistics but an Associated Press examination of news accounts during the 21 years since the Explorers was spun off from the Boy Scouts of America found at least 97 cases involving officers accused of sexual assault on minor girls, and sometimes boys, in the program. And that's likely a fraction of all such incidents, said Samuel Walker, a University of Nebraska-Omaha criminal justice professor and expert on police misconduct and accountability. Most relationships never become public because a youth is unlikely to report it and even if fellow officers are aware, they're reluctant to do anything. "More often than not other officers know that something wrong is going on and they don't report it," Walker said. "Police departments are like villages: everybody gossips and everybody knows." The Explorer program is run by Learning for Life, a subsidiary of Boy Scouts of America.