Rosen was a former Fort Bend County prosecutor and a well-known attorney who spent more than 20 years practicing criminal defense.
"We lost a great man today in Rocket Rosen," wrote the Fort Bend County District Attorney's Office in a Facebook post. "A formidable attorney and former Fort Bend County prosecutor, Rocket battled his ALS diagnosis with dignity, spending the last few years speaking to honor, character, resilience, and positivity. Rocket, it was our honor to know you."
Rocket is best known for his representation of two of the Branch Davidians after the deadly Waco siege of 1993.
Rocket posted many videos about his battle with ALS to his Facebook page, speaking of honor, determination and resilience.