The daily circulation of "Post" decreased in the final years of the Schiff era from 700,000 around 1967–68, to approximately 517,000 by the time she sold the paper to Murdoch in 1976. Under Murdoch, "Post" launched a morning edition to compete directly with the rival tabloid "Daily News" in 1978—prompting the "Daily News" to retaliate with a PM edition called "Daily News Tonight". But the PM edition suffered the same problems with worsening daytime traffic that the afternoon "Post" experienced and the "Daily News" ultimately folded "Tonight" in 1981. By that time, circulation of the all-day "Post" soared to a peak of 962,000, the bulk of the increase attributed to its morning edition (It set a single-day record of 1.1 million on August 11, 1977 with the news of the arrest the night before of David Berkowitz, the infamous "Son of Sam" serial killer who terrorized New York for much of that summer). But "Post" lost so much money that Murdoch decided to shut down "Post"s PM edition in 1982, turning "Post" into a morning-only daily.