FORT LAUDERDALE, Fla. - Defence attorneys for Florida school shooting suspect Nikolas Cruz are asking a judge to order investigators to preserve most evidence in the case, except for the building where the Valentine's Day massacre took place.

A hearing was set Thursday on motions seeking to preserve evidence including field notes made by law enforcement officials that may have some bearing on the case. The motions don't object to the planned destruction of the crime scene building where 17 people died and 17 others were wounded in the attack in February.

Delayed until a July 16 hearing is another defence motion seeking to prevent public release of Cruz's statement to detectives after the shooting. The Cruz lawyers say it would jeopardize his fair trial rights.

Nineteen-year-old Cruz faces the death penalty if convicted.