Daniel Leonard, 32 of Olympia, Wash., was arrested Monday as a suspect in a telephone stalking case. ((Police photo))

Police in California arrested a suspect Monday in a telephone stalking case that had victims so traumatized that they quit jobs, stopped answering their phones and were fearful they would ultimately be assaulted.  

Police alleged the man used a "spoofing" service, which caused a fraudulent telephone number to appear on the victim's Caller ID and a voice-altering device to mask his identity. The "spoofing" service made the calls almost impossible to trace.

Over the course of a four-month investigation, police said, the caller used the same modus operandi on multiple victims in other parts of California and across North America, including the state of Washington, Florida, Maryland and Canada.

Daniel Christopher Leonard, 32, of Olympia, Wash., has been charged in the case.