Kevin Burkhoff

Kevin Burkhoff (Jeffrey Combs) was a world-renowned scientist before suffering a mental breakdown and being committed to Abendson Psychiatric Hospital. He was fortunately cured thanks to a device constructed by Tess Doerner, a 4400 and fellow hospital patient.
After his "awakening," Kevin was hired by The 4400 Center where he helped uncover the NTAC promicin inhibitor that almost wiped out The 4400. Since then, Kevin has immersed himself in the study of promicin -- the chemical substance in 4400s responsible for their abilities. Determined to discover the secret behind the mysterious substance, Kevin began injecting promicin into his system to study the effects.