The Pelican Brief by John Grisham

In suburban Georgetown a killer's Reeboks whisper on the front floor of a posh home... In a seedy D.C. porno house a patron is swiftly garroted to death... The next day America learns that two of its Supreme Court justices have been assassinated. And in New Orleans, a young law student prepares a legal brief... To Darby Shaw it was no more than a legal shot in the dark, a brilliant guess. To the Washington establishment it was political dynamite. Suddenly Darby is witness to a murder -- a murder intended for her. Going underground, she finds there is only one person she can trust -- an ambitious reporter after a newsbreak hotter than Watergate -- to help her piece together the deadly puzzle. Somewhere between the bayous of  Louisiana and the White House's inner sanctums, a violent cover-up is being engineered. For someone has read Darby's brief. Someone who will stop at nothing to destroy the evidence of an unthinkable crime.