HARROWING BUS RIDE Mental health professionals and law enforcement use a machine that is meant to show the symptoms that mentally ill people experience. In this video dramatization, a person suffering from schizophrenia experiences hallucinations during a bus ride. The clip was prepared by Janssen, a unit of Johnson & Johnson that makes schizophrenia drugs. Warning: Crude language and intense visuals are used. Windows Media: HIGH | LOW Real Video: HIGH | LOW

Mr. Lopez and a group of 30 police officers from the Phoenix area were undergoing a simulated schizophrenic episode. It lasted just five minutes, but the officers were clearly relieved when it was over. One officer ripped off the headset broadcasting the voices. "This would drive me crazy," said Sgt. Barbara Alexander, "if I had to listen to it all the time."

The officers' taste of psychosis was supposed to give them new perspective on an increasingly common part of their work -- dealing with mentally ill people on the streets. The problem follows the shuttering of state-run mental-health facilities a generation ago. Prisons helped pick up the slack. The Justice Department estimates that about 330,000 of the nation's 2.2 million inmates are mentally ill. When released, they usually end up back in prison, in part because of a lack of outside treatment options.

Traditional police training runs counter to the tactics sometimes needed in encounters with sick people. Young recruits in police academies, for instance, are taught to take immediate command of unstable situations by shock and awe, issuing loud commands.

Mentally ill patients often react adversely to that. A Los Angeles study found that between 1994 and 1, officers there shot 37 people during encounters with the mentally ill, killing 25.

Now, hundreds of police departments nationwide are trying to change their approach. In San Diego , officers are paired with mental-health professionals on some calls. In Arlington , Texas , all patrol officers and new recruits are given training that ranges from identifying symptoms to knowing what services are available. Some departments direct calls that appear to involve mentally ill people to officers with special training.

The training began here in 2001 and was patterned after a program created in Memphis , Tenn., following the fatal shooting there of a mental patient by local police. Five years later, about 1,000 officers have been trained, and now even 911 dispatchers and some detention officers are getting some instruction. The program here is one of the largest in the country.