Jack Duffy was an Alpha who participated in Alpha street fights. He fought on top of a rooftop with Ivan Bazevich, where he was spat on with hydrochloric acid and fell to his death. Rachel examined his body and diagnosed the cause of death, leading to an investigation into the Alpha street-fighting ring. He was an Electrogene who could conduct electricity.
Interesting enough, Jack Duffy was able to produce actual bolts of electricity, something atypical to most Electrogenes.