the criminologist was sent over to the newspaper as were inspectors. and the two letters were examined and opened. >> the zodiac's reaching out to the police repeatedly and in great length was something new. >> the psychotic killer has already murdered five. one at a lover's lane near a lake just north of san francisco. three others in nearby vallejo. the latest, a taxi driver in san francisco. the zodiac killer seems to crave publicity. he sent letters and cryptograms to newspapers and the police recounting his crimes, threatening more murders and making bay area residents very edgy. >> in the '70s there was a certain kind of killer who had the skill to get away with murder long enough to assemble a body count where they would be classified as a serial killer. >> in los angeles, a killer the police are calling the hillside strangler, has murdered ten