These two letters came four years after the last Zodiac letter arrived on January 29th 1974, which stated "I saw + think "The Exorcist" was the best saterical comidy", three days after the 31st Golden Globe film awards at the Beverly Hilton, Beverly Hills, California on January 26th 1974, in which "The Exorcist" film won "Best Film", "Best Director", "Best Supporting Actress" and "Best Screenplay". Three consecutive communications that just happened to piggyback off award ceremonies for the film industry, that were all presumably conceived and written by Inspector David Toschi and/or Robert Graysmith according to some. If Inspector David Toschi wrote the April 24th 1978 letter, then he probably wrote all three of these letters, and had a hand in the phone call 42 days before the "I am back with you" letter, when somebody rang an individual living in the Mission District and stated "This is the Zodiac. Tell the press that I am back in San Francisco".
If the author of the January 29th 1974 (Exorcist), April 24th 1978 and May 2nd 1978 letters is one person (linked through a film industry theme), then where does that leave us with the July 19th 1978 letter, which has a common theme with both the April 24th 1978 and May 2nd 1978 letters? The author of the July 19th 1978 letter could have borrowed wording from the published April 24th 1978 letter, however, they did manage to continue the consistency in language used in the May 2nd 1978 letter, which they could never have seen if not the same person. The author on May 2nd 1978 and July 19th 1978, on both occasions, opted to mimic the verb "play" and singular pronoun "me" in the same sentence, from the April 24th 1978 letter. That probably leaves one author responsible for the last two letters. And if the May 2nd 1978 letter is linked by one theme to the January 29th 1974 and April 24th 1978 letters, then the July 19th 1978 letter is probably genuine too.
This consistency, now seen through four communications, would be implicating Inspector David Toschi in a much bigger hoax, who would have also investigated the "I am back in San Francisco" phone call on March 13th 1978 and then mailed the "I am back with you" letter the following month. Additionally, it could open the door to the similarities shown between the April 24th 1978 and Melvin Belli letters. Either David Toschi has played a leading role in fabricating many Zodiac communications, or he is responsible for none. The obvious choice seems to be none. Inspector David Toschi was a busy man, unlikely to be scouring the newspapers for Academy Award and Golden Globe ceremonies, KHJ-TV Studios polls and the World Chess Championships, to create common themes in order to manufacture an elaborate hoax. But there was one man that seemed to find the time. Bearing in mind that the author of the April 24th 1978 letter wrote "I am waiting for a good movie about me. Who will play me", it was quite ironical that the winner for best film in 1978 at the Academy Awards was a "satirical comedy", claimed by some to be semi-autobiographical about the life of "Allen". Woody Allen that is. The film was "Annie Hall", winner of four Academy Awards, not unlike "The Exorcist" movie, which won four Golden Globes on January 26th 1974