It happened around 11:45 a.m. Friday at Longhitano's Pizza on the 700 block of Street Road in Upper Southampton.
Employee Megan Colfer says the pizza shop was busy so she wasn't behind the counter at that moment.
Video released by police shows the woman wearing sunglasses and a heavy black coat with a scarf covering her face.
The suspect is seen glancing at the jar a couple of times and pacing a bit. Then she pulls out a plastic bag from her coat pocket. She walks up to the jar and quickly places it in the bag before walking out of the shop.
Upper Southampton police believe the woman is between 30 and 40-years-old.
Colfer says the money in the jar was for the Autism Cares Foundation and it was in honor of a close friend of hers whose son is autistic.
Megan says it's upsetting that anyone could steal from such a worthy cause.
Anyone with information is asked to contact police.
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