Crime Suspect In My Area ,will Police Pick My Call If I Hide My Number ,

Hello Everyone ,There are Some Guys ,I Suspect to be Armed Robbers in my area , Honestly, I want to Report them but I'm been Careful,I don't want to call the Police with my Number .About 9 years ago ,An Incident Happened in the Area we lived Before ,There was an Armed Robber suspect that was Reported ,the guy was picked up ,the police Ransacked his house they found a Gun ,To cut long story Short ,The Guy was Released after some Months ,The Guy with His Group came for the Reporter ,Robbed Him and Injured him ,He Lost His Legs. He was lucky they almost Killed Him ...We later found out that it was one of the Police that Pointed the reporter ,The Armed Robber and Police belongs to Same Cult Group .This is the Reason I'm been Careful ,I want to report these guys but because they Pose a Threats to us in this Community.I have number of some Police Officers ,I have not called them before so they won't Recognize my voice .Will they Entertain my Call if not Does Anyone Knows how I can Report a Suspect Anonymously?Pls Help