This is not the first notorious case in which Judge Kennedy has participated. In the prosecution of O.J. Simpson, when she was a municipal judge, she initially limited investigators to 10 hairs from Mr. Simpson's head for microscopic comparisons to hairs found in a blue knit cap lying near the bodies of Nicole Brown Simpson and Ronald Goldman. That "surreal" ruling reflected a lack of understanding of hair comparison protocols. [2, p. 230] However, the Grim Sleeper ruling is more mainstream. No court has treated collecting shed or inadvertently abandoned DNA as a search [3, p. 454]
Apparently, investigators did not want to alert Mr. Franklin that he was suspected of the long series of rapes and murders attributed to the Grim Sleeper. They had a police officer pose as a busboy at John's Incredible Pizza, where Franklin was attending a birthday party. Franklin argued that the officer-busboy cleared his plates — first pizza and then chocolate cake — before he had finished eating. and that this poor service made the collection unconstitutional.
One might not think much would turn on how close Franklin was to completing his repast. From time to time, I have had to tell an eager waiter reaching for my plate to wait -- I am not yet done. If a customer does not speak up, how can he be said to have a protected property interest in the plate, an interest that might trigger Fourth Amendment protection under United States v. Jones, 132 S.Ct. 945 (2012)? Moreover, if a failure to allow the restaurant patron time to eat all he wants is the source of the Fourth Amendment violation, the inevitable discovery exception to the warrant requirement could render the matter academic.
However, Franklin also claimed that he had a reasonable expectation that his plates would be thrown into a pile with others, making his DNA unavailable for testing. This is precisely the argument that the Supreme Court rejected in a questionable opinion in California v. Greenwood, 486 U.S. 35 (1988). In that case, police acquired sealed, plastic bags of trash that their suspect placed on the curb for municipal pickup. Greenwood argued that he expected that the bags would be mixed up with the other garbage in the neighborhood, preserving his privacy interest in the contents of his bags. But the majority of the Court deemed this expectation unreasonable because marauding dogs or curious people might go through the bags before the garbage truck arrived.
Even if that reasoning is convincing, however, the burden on the diner to take other steps to protect his DNA from inspection seems greater than that which Greenwood imposes on people to dispose of some parts of their trash privately. Judge Kennedy reportedly reasoned that "If [Franklin] were really concerned about such things, he would not eat or he would take his trash with him."  Is that the kind of world we want to have — one in which people who wish to keep their DNA to themselves must bring their own silverware, plates, and trash bags to restaurants or stay at home for all meals?
Thus, I think that the Fourth Amendment status of police collection of certain forms of shed or discarded DNA is a closer question that the caselaw suggests. There is a plausible argument that at least some surreptitious DNA collection from suspects amounts to a "search." Accepting this argument would not necessarily make this mode of DNA collection and analysis impermissible, for not all searches are unreasonable. But it would require more analysis of the individual and state interests at stake.
- Paresh Dave, Grim Sleeper: Judge Allows DNA Evidence Gathered at Restaurant, Los Angeles Times, Jan. 7, 2014
- David H. Kaye, The Double Helix and the Law of Evidence (2010)
- Albert E. Scherr, Genetic Privacy and the Fourth Amendment: Unregulated Surreptitious DNA Harvesting, 47 Ga. L. Rev. 445 (2013)
- MDNA, Forensic Science, Statistics, and the Law, Mar. 15, 2014