Authorities say a Shirley woman escaped police custody and stole an ambulette before leading police on a chase in Suffolk.

Melina Silsbe, 24, was being held last night on outstanding warrants when she complained of illness and was taken to St. Catherine of Siena Medical Center in Smithtown for observation.

One officer was assigned to guard her at the hospital. Silsbe allegedly wiggled out of her handcuffs and then managed to take off in an unattended ambulette that was idling outside.

After the escape, police say she led police cars to Jericho Turnpike in Commack and entered the Sunken Meadow State Parkway. The ambulette went into the woods and crashed into another vehicle, but the other driver was not hurt. Police say Silsbe suffered a minor eye injury in the crash.

Silsbe pleaded not guilty at her arraignment on multiple felony and misdemeanor charges. She is being held on $145,000 cash bail.

A departmental security review is underway following another similar escape last week at Good Samaritan Hospital's emergency room.

Suffolk police tell News 12 Long Island that all prisoners undergoing hospital medical treatment will now be required to wear leg irons to prevent future escapes.