The DOJ said that it was not reading Tsaraev his Miranda Rights because it was invoking a "public safety exception" with the argument being that they needed to get him to talk to make sure the public wasn't in danger. This is a short sighted decision that can only backfire.
Reasons: 1) Suspending basic rights and due process out of fear is exactly the kind of thing that people attacking the US want to see. 2) The slippery slope here is steep and extremely slick. The whole point of the ruling in Miranda is that it should not be up to law enforcement. 3) We're violating our basic principles, Constitutional due process. Turning ourselves into a paranoid police state without basic rights means that those who attack us are winning