By backchannel I meant via people. As in the Palantir analyst calls up their friends at the CIA/NSA for help. CIA/NSA data collection remains secret, Palantir justify their expense, and NYPD find the guy. The problem is that you can't reproduce your results. The other problem is the erosion of civil liberties - but I'm only speculating with a thought experiment.

I'm not sure why you'd assume that, the NYPD certainly has a history of bravery but not one of technical competence.