The Allegheny County medical examiner's office says Ecker was 84 when he died in his sleep of natural causes before his body was found about 9 a.m. Wednesday.
Ecker cut a distinguished figure with his white hair and dapper dress.
Among others, he represented John Vojtas, a Brentwood police officer acquitted in the death of Jonny Gammage, a black motorist and cousin of then-Pittsburgh Steelers player Ray Seals, who died during a 1995 traffic stop. Ecker also represented Thomas Hose, a former school security guard serving five to 15 years in prison for keeping a female student captive for a decade.
Law partner Brent McCune says Ecker "was the ringmaster" in many high-profile cases.