Now that Los Angeles has settled the political questions of where rapid transit trains will run, roughly how much they should cost and who will pay to build them, the Southern California Rapid Transit District faces an equally sticky decision:

Will its transit police be able to police its transit?

The RTD's Board of Directors is scheduled to decide today whether to let its 192-officer Transit Police Department patrol the Metro Rail Blue Line--and, implicitly, all other mass transit lines being built--or renew its current contract with the Los Angeles County Sheriff's Department.

At stake are the security of Blue Line passengers as they pass through some of the county's toughest gang turf, and the honor of RTD transit police struggling to shed their unprofessional image. Transit police are currently limited to patrolling buses and bus stops.

At issue is how badly the sheriff's $12-million annual fee helped bloat the Blue Line's first-year $28-million operating deficit, and the value of safety in luring passengers to what eventually will be the nation's second-largest rapid transit network.

"With the Blue Line, we established a standard the public deserves," said Neil Peterson, executive director of the Los Angeles County Transportation Commission, which pays for all of the buses and trains that the RTD operates. "We can't downgrade that standard."

RTD Police Chief Sharon K. Papa rejects the idea that her department means lower standards, because she believes it is uniquely prepared to patrol trains. "It doesn't make sense," she said, "to have an agency that specializes in transit policing but doesn't police the transit system."

Politicking has been heavy--and heavy handed. Sheriff's deputies handed pre-addressed post cards to Blue Line riders this summer, inviting them to evaluate law enforcement on the train. The LACTC has commissioned telephone polls and convened focus groups to beef up its support of the Sheriff's Department. RTD police show up in force, and in uniform, at every board meeting where the issue is discussed.

The RTD board backed the Transit Police two years ago by voting to let them patrol the Blue Line. But the board reversed its decision seven weeks later--embarrassing itself and its officers--after collapsing under intense political pressure from Peterson, Mayor Tom Bradley, and the Board of Supervisors.

Five of the RTD board's 11 members are appointed by the supervisors, and two more serve at Bradley's pleasure.