SKOWHEGAN (AP) – A Portland man diagnosed with schizophrenia and charged in the slaying of a cab driver has waived his right to a jury trial.

Derek-Finn Wilhelmsen, 21, has twice been found incompetent to stand trial for murder, but Wednesday’s court proceedings set the stage for a bench trial next month.

Wilhelmsen is accused of shooting Portland cab driver Nunzi Mancini, 38, several times in a driveway on Route 100 in Pittsfield.

Wilhelmsen said he took the taxi to Pittsfield in February 2002 with the intention of killing his ex-girlfriend but instead shot Mancini when the cab driver insulted her, according to police.

In the years before his arrest, Wilhelmsen had been diagnosed with schizophrenia, and his condition was exacerbated last summer when he suffered a serious head injury while a patient at the Augusta Mental Health Institute, said M. Michaela Murphy, Wilhelmsen’s lawyer.

Both a state examiner and a forensic psychologist hired by Murphy found Wilhelmsen incompetent to stand trial. Murphy said the psychiatric and psychological testing will show that Wilhelmsen was unable to control his behavior.

But prosecutors have said that Wilhelmsen’s mental status will continue to be a factor and that competency can change over time.

The trial is scheduled to begin May 12 before Justice Nancy Mills.

AP-ES-04-03-03 0940EST