The dark-colored mask was found under a pile of leaves by a resident on Saturday morning.
The mask has been sent to the FBI lab in Virginia for processing.
The attempted abduction happened shortly before 7:00 a.m. on Tuesday, November 10th at Sulky Way and Trotters Lea Lane in Bethel Township, Pa.
Police say that's when a man, dressed all in black and a ski mask, approached a 12-year-old girl, pulled out a knife, and tried to take her.
The school bus then pulled up and the man fled.
Her father tells Action News the girl told authorities what happened when she got to school, and then came right home. Her father, it turns out, is a police officer in another town.
Using a K9, police say they were able to track the suspect into Delaware.
The girl is a student at Garnet Valley Middle School.
Anyone with information regarding this incident should contact the Bethel Township Police Department at 610 558-0929.