At Oak Hall, the rules are strict but simple. You must be at least 25 years old, clean and sober, and able to live cooperatively on a floor with five other people. But one tenant there still drinks, and he’s not just quietly nursing his bottle. He pulls out knives, threatens neighbors, gets in fights, breaks furniture and windows. The other residents hide in their rooms, afraid to come out even to cook dinner.

“When one person is refusing services, it’s a disservice to all the tenants and that person,” said Carolyn Walker, a case manager at Oak Hall, a single room occupancy residence for mentally ill people in Fort Greene.

But finding a new home for someone who won’t stick with the program is not easy. Hard-to-place cases often wind up back living on the street or in shelters, where they can wait months for an appropriate place to live–or never come back for help at all.

So a pilot program set to begin next month in Brooklyn holds great promise. Run by the state Office of Mental Health, the new “single point of entry” system is a centralized registry designed to speed mentally ill homeless people into supportive housing, where residents can get psychiatric care right in their own buildings. A database will match clients with suitable vacancies. The registry will also track who does not end up getting a place to live and why–and hopefully make sure fewer of the homeless mentally ill remain without a place to live.

The state believes that centralization will simplify the job of getting clients with complicated situations–from health problems to pyromania–the specialized help they need in supportive housing. But the groups providing those rooms say it will put pressure on them to take on clients who don’t fit–who could disrupt the delicate balance their programs need to work and demand help that their staff is not able to provide.

Until now, it’s been up to social workers at shelters, rehab, prison and hospital psychiatric units to refer clients to appropriate supportive housing. Armed with a potential client’s mental and medical history, the housing facility in turn decides if the match is a good one.

But starting with the Brooklyn pilot and phasing in citywide by the end of the year, all applications for housing will be routed through a database run by the Center for Urban Community Services (CUCS), a major nonprofit provider of supportive housing, which will come up with three placement options. The social worker must send that client to those programs, all three of which must interview and decide within two weeks whether to take him or her.Jan Tacoronti, the system’s project coordinator for New York State, says the idea is to streamline a haphazard and largely unaccountable process that too often leaves homeless people wandering. “Sending out referrals like a shotgun is a waste of effort,” Tacoronti says.

But many housing providers see an important selection process at work amid that apparent inefficiency, reports David Bergman of the Coalition of Voluntary Mental Health Agencies, because many social workers insist on sending their clients to housing programs with good track records. “We know to send clients to places that have been respectful to our clients…where people have helped our clients,” agrees Tena Frank, director of homeless services at the Lenox Hill Neighborhood House. “It’s built on trust and experience.” Housing organizations rely on that same trust, too–for assurance that a social worker isn’t withholding compromising information about a candidate’s history, for instance.

But such mutual support, say designers of the centralized booking system, doesn’t insure that tough cases find homes; in fact, it often allows providers to pick the best-behaved clients while turning away the people who are in the most serious need of help. Project directors hope to put pressure on homes to take complicated cases that would normally get rejected.

“It’s accountability in a system that’s not accountable at all,” says Suzanne Wagner, the director of Residential Placement Management at CUCS, where the database has already been in use for a decade. Right now, no one keeps an eye on who actually ends up in supportive housing after getting a referral and who stays homeless. “We know where people get placed, but not how many places they went first or what happened to them if they didn’t get placed,” Wagner says. “Some people are getting hospitalized three or four times a year, and when you see that application, you know something’s wrong.”

In Westchester, where a centralized referral system has been in use for two years, supportive housing facilities are now accepting clients they used to turn away, says Susan Erway, the county director of community support services. “It insures access to housing for high-need clients,” Erway says, such as those who start fires. “Now we ask, ‘What would you need to house this person and what can we give you to do that?’”

City housing groups will likewise be offered extra help. If all three recommended housing providers reject an applicant, they’ll need to meet with CUCS and a state representative to figure out what additional services the state could supply–such as intensive psychiatric help or outpatient rehab–to make it possible for one of them to accept the person after all. Young adults and the elderly have the hardest time finding housing, says Walker, because few programs are tailored to their needs, like long-term medical support or substance abuse treatment.

Indeed, the central check-in system’s greatest promise is that it will show the state exactly where the holes in the support net are and push officials to develop programs to fill them. That’s worked before: In 1998, advocates for the homeless won more than $130 million for new supportive housing, in part by using information from CUCS’s database to demonstrate that there just weren’t enough places for the homeless mentally ill to live. “Getting more data will help fill the gaps,” Wagner says. “What kind of beds do we need? Do we need to develop new methods of housing?”

In the complex relationship between supportive housing groups, their clients and the state, trust is slowly growing. Although some housing providers worry that a centralized referral system will leave them vulnerable to whatever Albany wants them to do, they’re also hoping it will speed the homeless mentally ill directly to the care they need. “Generally, we are cautious,” Bergman says. “It’s a noble effort, and if it works, we applaud it.”

Nora McCarthy is a Brooklyn-based freelance writer.