I can understand everyone's confusion....and the "info" provided by the police is not helping alleviate that much.
As for the 2 arrested men and the "note," the police believed that the note was left by the sniper and that he (they) were trying to open dialogue with the police. He/they left a number that they would contact. I do not believe it is a number that they would be calling from but rather calling to. The police had to scramble to clear the number that was provided. It is believed that the individual(s) who left the lengthy note did contact the number and that is how the police were able to trace the number and, subsequently, arrest those 2 individuals.
Those 2 idiots, it appears, are NOT related to the sniper but were trying to capitalize on others misfortunes. From the info I've heard, they were trying to extort money. Of course, they are not in a position to offer any guarantees that the sniper(s) would not hit again. They are being deported.
Hope that clears up some of the confusion.