[FootBall]

But what makes C.O.P. Moose believe the sniper would be gullible enough to fall for his "call me back

I think Moose and task force is purposely insulting this guy so they have a chance at catching him on his next shoot and hope no one gets killed. I think they have little if any real evidence and can only catch him if he continues to hunt. OR they are one more shooting from catching him.

[SCR1]

Exactly, and that is why the released the info about the threat to the children. I guess having a bunch of dead kids on their hands might be too much for some of them and they decided to let the parents decide the fates of their own children while they allow the sniper to continue to hunt.