[header] How to report extortion [title] Collect your documents or information. [step] Police will want copies of anything you may have, such as letters or voice mail messages, that could provide evidence of the crime. [substeps] You can check your state's law to learn the elements of extortion. 
These elements are what a prosecuting attorney must prove to have someone convicted of extortion. If you don't have evidence of enough of those elements to constitute probable cause that the person committed the crime, police may not investigate your report.