The Zodiac Killer had a long memory, often referring to newspaper headlines and the content within them from many months and years earlier. On Saturday, November 1st 1969 the Vallejo Times-Herald ran an article entitled You Couldn't Tell It Was Halloween, expressing surprise that the Zodiac Killer had not written or made an appearance during the Halloween festivities, writing "He made no threats - in fact, he did not even communicate to police departments in the Bay Area about any plans he may be developing for Halloween. Nevertheless, parents and youngsters alike were on the extremely cautious side". Vallejo Police Chief Jack E. Stiltz warned it could be a very dangerous time for youngsters to be on the streets. Whether the October 28th 1987 Zodiac letter was just a product of fortuitous language, or whether the Zodiac Killer religiously kept a scrapbook of newspaper articles about himself, is unknown. But this letter stated "Tell the blue pigs if want me I will be out driving around on Halloween in my death machine looking for some kiddies to run over. Cars make nice weapons. The pigs can catch me if They can find me out there. Just like in the movie The car. Tell the kiddies watch before They cross the street on halloween nite". Regardless of this distant communication, the following Halloween after this article was published, the Zodiac Killer mailed the October 27th 1970 Halloween card to Paul Avery, referring to teenagers through the use of the word "TEEN", failing to use his pseudonym, and supplying us for the first time with the character "Z" as his identity. He also selected a greeting card suggesting he was going to clue us in on his name, beginning "I feel it in my bones, you ache to know my name, and so I'll clue you in." The answer once the card was opened was "BOO".