Dominic Kretzger's (security guard/suspect) attorney mentions Richard Jewell as a reason he needs an attorney. Richard Jewell was the security guard at the Atlanta 1996 Olympic games who saved countless lives after discovering a bomb and evacuating people. He was slandered in the media as the bomber, seeking to attain hero status. In fact he was cleared of all charges and the real culprit (Eric Rudolph) was apprehended in 2003 after several other bombings and years as a fugitive on the FBI'S 10 most wanted.
The newspaper clipping at the end of the episode contains the same paragraph text repeated three consecutive times in order to make the article appear long.
At the site of the first bomb, Grissom tells his team that "If it's not growing, pick it up." These are the same instructions given to the searchers and investigators following the Lockerbie bombing in 1988.
Part of the bomber's signature involves engraving the letters "FP" onto certain components of his bombs. This is similar to the signature used by George Metesky, the Mad Bomber of the mid-20th century, who signed the notes that accompanied his bombs with the initials "FP." In both cases, this stands for the words "Fair Play."
Mark Valley plays two different characters, one in the first season, and Daniel Shaw in the last few seasons.