When a new Justice arrives, it is common to ask how the new Justice might vote differently than the Justice she has replaced. A recent speech by retired Justice John Paul Stevens gives us relative clarity on one example. In his speech, Justice Stevens explained that he likely would have voted with the majority in Maryland v. King, the recent 5-4 decision upholding DNA collection and analysis on arrest. His replacement on the Court voted the other way: Justice Kagan voted with the dissent, making the case 5-4 instead of what would have been 6-3. You can read Stevens’ explanation of why he would have voted with the majority here from pages 12-17.
Putting aside the propriety of a retired Justice announcing how he likely would have voted in a recent and controversial case — a question on which reasonable people will disagree — such a vote would have been consistent with Justice Stevens’ past Fourth Amendment decisions. More than other Justices, Stevens tended to focus on the degree of privacy implicated in the specific information obtained by the government — what I have called the “private facts” model of the Fourth Amendment search test. Thus he dissented in Kyllo (in which the thermal imaging device only revealed the temperature profile of the wall), and he authored the Court’s two major decisions concluding that methods of evidence collection that only reveal the presence or absence of narcotics are not searches (Jacobsen and Caballes, holding that drug tests and dog sniffs in the field are not searches).
Thanks to How Appealing for the link.