MOUNT KISCO, N.Y - A suburban police chief called for patience yesterday as a neighboring department investigated the possibility that his officers had been involved in the death of a homeless man.

Police in Bedford, where Rene Perez was found dying on a roadside April 28, have confiscated two Mount Kisco police cruisers as part of their investigation. The cars were being examined yesterday by the Westchester County forensics lab, the Bedford police said in an e-mailed statement.

Mount Kisco police have acknowledged that three officers had responded to a 911 call placed by Perez from a Mount Kisco coin laundry an hour before he was found in Bedford. The officers determined that Perez "did not have a police matter," the department said.

Perez, 42, a Guatemalan immigrant, had a long arrest record and had problems with drunkenness with making 911 calls in Mount Kisco.

The county medical examiner has classified Perez's April 29 death, from internal injuries, a homicide.

Mount Kisco Chief Louis Terlizzi, meeting reporters outside his headquarters yesterday afternoon, said, "I encourage both the public and the media to be patient."

"The Mount Kisco Police Department is seeking the truth regarding the death of Mister Perez and will accept nothing less," he said.

He refused to say why the cars were being examined, referred questions to the Bedford police and then turned and walked back into the building, ignoring reporters.

Bedford police refused further comment, and county District Attorney Janet DiFiore said she was "not in a position to comment."

Two Guatemalan immigrants were found strangled in Mount Kisco six months apart in 2003 and 2004. The killings are unsolved. *