So I've wondered this too. We had two very high profile cases near me - the Austin bomber and the HB / MF baby abduction/murder case, and all of the press updates for the bomber were by our police chief, and in the other case, also APD updates. I can't even remember with Kenneth McDuff or the yogurt shop murders any pressers by non local LE. The closest we have to the ISP is the DPS and I can't remember any DPS pressers on high profile cases - maybe someone else can.
It has interested me from the start. Might just be because of the FBI involvement and it being such a tiny town. But in the two cases I listed, both had FBI involvement, and homeland, as did Delphi >
Grandfather of one of murdered Indiana teens speaks out | Daily Mail Online.
I'm just assuming ISP is the lead, and not the local sheriff. Is that because there's state jurisdiction because of the park? I'd love to know.