Logic never has been MSNBC's strong suit but I've never seen them be so casual with cause and effect. "How did killer become a sheriff's deputy?" is the title of the linked article's page. Now what does this title make you think? The statement is clearly worded to give you the idea that someone who was a killer is now a sheriff's deputy but that is hardly the case. A sheriff's deputy became a killer. Not the other way around. Just because A -> B, that doesn't mean that B -> A.*
Here's the meat of this obvious abuse of causality:
“The first statement we said to each other was, how did he get through the system?” Franz said. “How do they know somebody’s background, especially that young? It is disturbing, to say the least.”
Background implies things that happened in the past. Unless you have a Police Box that's bigger on the inside or a phone booth given to you by none other than George Carlin, it's going to be kind of tough to get background info on something that hasn't happened yet. If anything, the background of someone so young should be a lot easier to figure out than someone who is older. This guy's background came up clean but he still murdered 6 people. It's a tragedy but it looks on the surface like one that couldn't have been stopped.
I do sincerely hope we don't become a nation obsessed with precrime, because we don't the technology to do anything about it.
* That's a little discrete math for you. -> is the symbol for implies. Given the time constraints of the word "become" it is clearly an implication rather than an equality.