The Zodiac Killer didn't personally name any of them, but referred to them indirectly when he stated "two cops pulled a goof", "I hope you do not think that I was the one who wiped out that blue meannie with a bomb at the cop station" and "I shot a man sitting in a parked car with a .38". Additonally, all three communications carried the message of his bomb-making.
It is highly unlikely that the Zodiac Killer was responsible for the murder of Sgt. Richard Radetich, with the previous observations just a simple case of unfortunate coincidences, but it still leaves pause for thought when you consider the location of the bomb had been earmarked in a letter two months in advance of his murder, on April 20th 1970. A letter that highlighted the bombing of Park Police Station and the murder of Brian McDonnell, with the claim that "It just wouldn't doo to move in on someone else's teritory". So, did the Zodiac Killer move to a territory slightly south of Park Police Station, the clue to which lay in the attached bus bomb diagram?