Now that the show is back in syndication, I've watched as many as I can and see some major differences between the early shows (1965 or so) and later ones (in the early 70s). The early ones SHOWED more violence and often the bad guys were "pushing up daisies" by the end of the show. Later, the FBI agents hardly ever shot the bad guys or if they did it was just in the leg or arm--hardly realistic, but an apparent bow to overly sensitive pressure groups that had grown in the early 1970s. Also, while Inspector Erskine shot a lot of crooks, they tended to be non-lethal shots in later shows.
Another difference is by the end of the series, the FBI and its abuses had come to light...such as warrantless wiretaps, warrentless breakins and the like. So, to counter this, Inspector Erskine OFTEN would ask things like "makes sure we have a warrant"!
Finally, the earlier episodes made the characters seem a little more human--often, Erskine was shown with a good looking woman or would complain about having to work too hard, while later he was pretty much a robot. Finally, the earlier episodes were occasionally more histrionic--sometimes too much and some times very juicy and exciting! In general, I prefer the earlier shows--they may have been a little campier, but they seemed more exciting. Still, despite this, it's an exceptional series and holds up very well today.
