Charles Shaffer, Warren Commission staffer who changed his mind

Charles N. Shaffer Jr. did just about everything right in representing John W. Dean III, the onetime White House counsel whose riveting testimony before a Senate committee in 1973 directly implicated President Richard M. Nixon in the Watergate break-in and coverup, leading to Nixon's resignation the following year.

But Shaffer, who died at age 82 at his …