Explosives Threat Bandit William Allen
This surveillance camera image shows the "Explosives Threat Bandit" William Joseph Allen, 32, of Los Angeles during a Nov. 15, 2011 robbery at a West Covina Bank of America branch. He has pleaded guilty to six counts of bank robbery and attempted bank robbery and was sentenced to more than 11 years in prison on Thursday, March 28, 2013. (Courtesy of the FBI)

LOS ANGELES -- A serial bank robber dubbed the "Explosives Threat Bandit" by the FBI has begun serving an 11-year prison term for bank robberies and attempts throughout Los Angeles County, court documents show.

William Joseph Allen, 32, of Los Angeles, pleaded guilty last year to six counts of bank robbery and attempted bank robbery. He was initially charged with eight counts, however two were dismissed under a plea agreement.

At his March 28 sentencing in federal court in Los Angeles, U.S. District Judge Philip S. Gutierrez sentenced the convict to 140 months in federal prison, along with three years of probation upon release and restitution in the amount of $26,125, according to court records.

Linked to as many as nine bank robberies and attempted bank robberies in Los Angeles, West Covina, La Puente, Pico Rivera, Venice, Santa Monica and Marina Del Rey, the bandit earned his moniker for threatening to have a bomb, according to the FBI.

The robbery spree took place between November of 2011 and March of 2012.

In some cases, he left behind large manila envelopes with wires protruding from them, resulting in bomb scares, officials said. Though ultimately found to be inert, the devices resulted in bomb scares. Allen was also known to carry a handgun during his heists.

He was identified and arrested by Los Angeles police officers in April of 2012.