It's definitely very possible, though I have two cautions. 1) Police do not take investigating their own lightly and thus most likely have very strong evidence

It's definitely very possible, though I have two cautions. 1) Police do not take investigating their own lightly and thus most likely have very strong evidence. 2) I don't know the details of these fellows' careers, but presumably they know procedure, know good defense attorneys and would be far more capable of assisting in their own defense than the average citizen.