You go after the segment of the investigation you've got the best evidence on, and you use that as leverage for your case. This is a prime example of that.

Let the investigation go forward, ... The investigation has to be comprehensive, all the evidence has to come out, there has to be full cooperation with the investigation by all parties.

Criminals Attack Discovery When They Can't Defend The Crime.

The commercial segment produced the best results,

The ballistics evidence uncovered during our investigation has been matched with the other shooting cases,

The investigation just never did produce any solid physical evidence of any kind.