^I was going to ask if you'd watched any other police shows. This is pretty standard stuff. They get the perpetrator off of flimsy evidence sometimes. And as for them not finding the evidence until the end that's just how it goes. They didn't know of the video to begin with. You can't expect them to walk into a crime scene and immediately assume there is a video. Once they found out there was a video they got to work on it.
For cop shows the big evidence, revelation, or things of that ilk usually don't appear until the last 10 minutes. They can't catch the bad guy 30 minutes into the show. What would they do for the rest of the episode? If they do ever catch the person a half hour in then you know damn well something else is going to happen (it's not the right person, the killer themselves will be killed, there is an accomplice, etc). It's just how it goes.
As for the killer confessing, I do usually think it's funny how they just go "eh, ya got me, so I'll just tell you everything", but in a show like this it's almost a necessity. These types of shows don't follow the case into the courts (with a few exceptions), so in order to give the audience some closure they have the killer confess. It's not perfect, but it is what it is.
In terms of Bones, I don't even really watch for the cases. I mean, I like them, but what I like the most are the interactions between the characters. The only cop shows I really watch anymore are the ones that are just as much about the characters as the crime (Castle, NCIS, etc).