One word:
REWARD
I think this guy was thinking he might be lucky enough to collect the reward offered by Padilla. So he just kept on phoning in “tips”, hoping to hit the Bingo.
Maybe not the most noble of motives, but rewards don’t require noble motives.
He called in the tip line on the same area as he walked by the same garbage bag over and over and the police came out and never checked out the garbage bag. Must have been too messy for them to get into the swampy underbrush and they didn’t bother.
He didn’t just call in with random places.