The pelican brief by john grisham

Two Supreme Court Justices are dead, their murders unsolved.
But one woman might have found the answer – if she can live to tell it.

Darby Shaw is a brilliant New Orleans legal student with a sharp political mind. For her own amusement, she draws up a legal brief showing how the judges might have been murdered for political reasons, and shows it to her professor. He shows it to his friend, an FBI lawyer.

Then the professor dies in a car bombing.