[PAR] [TLE] Zodiac Killer [SEP] The Zodiac Killer or Zodiac was a serial killer who operated in northern California in the late 1960s and early 1970s.  The killer's identity remains unknown.  The Zodiac murdered victims in Benicia, Vallejo, Lake Berryessa, and San Francisco between December 1968 and October 1969.  Four men and three women between the ages of 16 and 29 were targeted.  The killer originated the name "Zodiac" in a series of taunting letters sent to the local Bay Area press.  These letters included four cryptograms (or ciphers).  Of the four cryptograms sent, only one has been definitively solved. [PAR] [TLE] Dirty Harry [SEP] Dirty Harry is a 1971 American action crime thriller film produced and directed by Don Siegel, the first in the "Dirty Harry" series.  Clint Eastwood plays the title role, in his first outing as San Francisco Police Department (SFPD) Inspector "Dirty" Harry Callahan.  The film drew upon the actual case of the Zodiac Killer as the Callahan character seeks out a similar vicious psychopath.
[PAR] [TLE] Zodiac Killer [ SEP ] The Zodiac Killer or Zodiac was a serial killer who operated in northern California in the late 1960s and early 1970s . The killer 's identity remains unknown . The Zodiac murdered victims in Benicia , Vallejo , Lake Berryessa , and San Francisco between December 1968 and October 1969 . Four men and three women between the ages of 16 and 29 were targeted . The killer originated the name " Zodiac " in a series of taunting letters sent to the local Bay Area press . These letters included four cryptograms ( or ciphers ) . Of the four cryptograms sent , only one has been definitively solved . [PAR] [TLE] Dirty Harry [ SEP ] Dirty Harry is a 1971 American action crime thriller film produced and directed by Don Siegel , the first in the " Dirty Harry " series . Clint Eastwood plays the title role , in his first outing as San Francisco Police Department ( SFPD ) Inspector " Dirty " Harry Callahan . The film drew upon the actual case of the Zodiac Killer as the Callahan character seeks out a similar vicious psychopath .
What period of time was the serial killer that inspired the film Dirty Harry active?
What period of time was the serial killer that inspired the film Dirty Harry active ?
December 1968 and October 1969
December 1968 and October 1969