Investigators raided a Hell's Lovers motorcycle gang in Denver Friday night. Many of the motorcycle gang suspects are now in jail awaiting a court hearing Monday. The arrests come after a near three-year investigation by the Federal Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF agents raided the home and arrested at least 15 gang members for "violent crime." "We are not talking about traditional gang violence with younger youth that are from 17 to 24, which make up the bulk of gang violence. We are talking about...grandfathers even; some of them have different professions," says Terrance Roberts, a gang expert. The gang was formed in Chicago in the late 1960's, and has now spread to Colorado, Georgia, Maryland, Tennessee and Texas. Agents say the gang has been associated with cocaine trafficking and use of weapons and explosives.