When matching shoe prints by using several books Warrick discovers that the print is a match to Converse All Stars, Nick Stokes replies you needed all the books for that the soles been around 20 years. Converse All Stars were first produced in 1917 this episode takes place in 2000 which would make them 83 years old.
This episode "Anonymous" formally establishes that long unspecified periods of time can pass between each episode, as within the story universe the first part of this story happened 3 months ago, in the "Pilot" & "Cool Change" episodes although this is only episode 8, 2 months from the broadcast of the Pilot episode in real time. In addition, other episodes reference the events of the previous episode, implying one continual story arc.