Reno 911 is essentially a parody of the popular American TV show Cops and is made all the more effective in it's lampooning by the fact that like the UK and US versions of The Office - it actually appears to be genuine. The show features no canned laughter or clever editing and is all the better for it.
Basically, if you were to miss the opening credits, which display the actor's names, you could be forgiven for thinking you were watching a fly-on-the-wall style documentary about an incompetent Sheriffs department.
Another factor that gives the show an extra realism element is the part scripted and part improvised format. The characters all appear to be completely natural and do not appear to be scripted in any way.
The show focuses on the daily routines of a small Sheriffs department in Reno, Nevada, and typically sees the Sheriff and his deputies making a complete hash of any given scenario, arrest or crime scene. Of course there are the odd recurring sketches (crashing cop cars, stolen bikes and car-door wounding) but overall, every episode is fresh and funny.
-Review excerpt by Richie Caldicott on Helium.com