From what I've read they can go back ten years if you were not sentenced to jail time and 15 if the crime did include jail time. I've had 3 nonviolent marijuana charges since 1977.The last one was in 1999 for 1000kg of marijuana for which I got Federal jail time. The other charges were state charges that resulted in probation.1977 I had a 30 lb marijuana charge and in 1986 I had a 6 lb marijuana charge..no guns involved. No weapons involved in any of these charges. If a guy I know who just got popped for 18 lbs of marijuana snitches and brings me into the conspiracy will I be facing a career criminal enhancement ?