complete box set help.series help required from fans

bought the COMPLETELY WIRED dvd boxed set recently,did not use to watch thisoften (shiftwork) but lots of people loved it and I liked ROBSON GREEN in CASUALTY and HERMOINE in SPOOKS and I like police shows so will give it a shot.

But the boxed set is confusing,some episodes are called CASE FILES and others just have an episode name,why is this ?,was the series made is short stops and starts at first?

I am not sure I can face so many extreme killers,there must be more serial killers in this series than there have ever been in the whole of Britain?

1992 Britain looks like longer ago than that,guess I am getting old?