For the ABC News program Primetime Thursday in 2002, Cydne Holt of the San Francisco Police Department crime lab developed a partial DNA profile from saliva recovered from the stamps and envelopes of the Zodiac letters, notably the stamp on the November 8, 1969 card. The lab compared this profile to Arthur Leigh Allen and to Donald L. Cheney. Neither test result indicated a match, so both men were excluded as the source of the recovered DNA. The sources emphasize that a partial profile is limited evidence: it can include a person as a possibility or rule them out, but cannot single out one individual.