[lelio]

It sounds like the cops staked out that phonebooth, perhaps these jokers in the van used it before to make a tip line call and demand ransom?
My tinfoil hat theory is that the real sniper knew that these people were using this phone and wrote it down on the tarot card to get them busted.

[ScholarWarrior]

If your theory is correct, that means the perp knows someone on the inside. The number would be need to know info, 15-20 people tops.