A 9-foot shark turned up last week at Cape Cod with a mysterious red face and belly.
The Massachusetts Environmental Police posted photos Facebook saying it had washed ashore in Truro.
Scientists performed a necropsy on the male shark while it sat on the beach.
They discovered that it had three lead weights inside it.
Researchers also took samples from the carcass for study but could not say what killed the shark or what caused its redness.