Authorities say 13 bald eagles found dead near a farm on Maryland's Eastern Shore did not die of natural causes.
Necropsies of the birds confirmed they didn't die from disease or any other natural cause, Maryland Natural Resources Police said Thursday. The investigation will now turn to finding human causes and suspects.
So far, investigators know the birds were not shot.
Bob Edgell discovered some of the birds on his Federalsburg farm in February and described their bodies as having been "flattened."
The birds may have eaten poisoned rodents or could have been killed by a chemical someone sprayed on a field, Maryland Natural Resources Police spokeswoman Candy Thomson said last month. But Edgell says he hasn't laid any poison on his farm.
Thomson says bald eagles are no longer considered endangered in Maryland, but it is still illegal for people to kill them.
A $10,000 reward is being offered for information that leads to a conviction in the case.