Beginning Thursday, the Police Department will encrypt its police radio transmissions, with the scrambling of messages on private scanners intended to protect officer safety, according to a department spokesman.  Mayor Domenic J. Sarno and Police Commissioner John Barbieri, in a press release issued Wednesday at 5:35 p.m., said the encrypted radio transmissions are part of a recent project to upgrade to the police radio transmission system.  Sgt. John Delaney, an aide to Barbieri, said the “criminal element” are among the people listening to police scanners, to help follow what the police are doing and to aid their crimes. It also poses a danger to police, he said. Springfield police will scramble all radio communications, citing ‘criminal element’ that listens to scanners