The SPLC is actually working with the FBI right now on some old cases from the 1960's when civil rights demonstrators and activists were attacked.
The Justice Department is taking info from SPLC in its investigation into these old cases to see if federal charges can be brought on people who were never caught or successfully prosecuted in state or local courts in the 1960's.
A link to a story on this is:
http://www.wsfa.com/Global/story.asp?S=6135662&nav=ORdE