Personal Info:
Real Name: Michael Christian Amar
Also Known As: No known Alias
Place Of Birth: Unknown
First Appearance: Flash: Iron Heights (2001) Modern Age Villain
Known Associates: Blacksmith, Plunder, Girder, Tar Pit, Double Down, Weather Wizard, Trickster
Group Affiliation: The Society, The Rogues
Base Of Operations: Central City, Keystone City
Grudges: The Flash
Creators: Geoff Johns and Ethan van Sciver
Gallery: Click
Murmur has no super human powers however; has unusual blood chemistry, which makes him immune to lethal injection and the frenzy virus. He is also an expert with knives.
Nine years ago, respected surgeon Michael Amar went mad and began a killing spree to "stop the voices." He cut a swath of terror through Central and Keystone cities until he was captured by Fred Chyre and Joe Jackam. Convicted in part by evidence uncovered by police scientist Barry Allen and partly on his own uncontrollable outbursts, Amar - or "Murmur" as he had become known - was sentenced to death.
Due to his abnormal blood, it wasn't clear that a lethal injection would actually kill him, and Murmur spent the next nine years in Iron Heights. While there, he cut out his own tongue and sewed his mouth shut to make sure he would never incriminate himself again.
Murmur at DC Database
Murmur at Flash: Those Who Ride The Lightning
Murmur at Comic Vine