Nicholas Pike (commonly known as Pike) was a member of the police department who became a crook and a bike gang leader.
At some point, Nicholas Pike became a cop and was the partner of Jay Allen. However, while Jay became a commander, Pike turned rogue and turned to leading the Dark Riders, being feared by the public.
Vengeance on Jay Allen and arrest
Pike continuously terrorized citizens at night, having his men drive bikes around Central City at night and wreaking havoc, gaining the attention of the press. He then personally went after Jay Allen and brutally killed him after a short battle. This enraged Barry Allen, Jay's brother, who used his newfound super speed to take down Pike. Pike initially had the upper hand, but Barry managed to use his speed to wrap Pike in electric lines, apprehending him.
Revenge against the Flash
Pike is later released from prison due to a technicality and sets to kill the Flash. He attempts to kill him with a missile, however only managed to blast him to the future. Upon Barry's return, Pike is subsequently caught and sent to prison again.
In an alternate future where Barry's identity is made public, Pike rules the dystopian Central City. This future was presumably erased when Barry arrested Pike back in the past.