The police are not allowed to stop someone for no reason, but there is a longstanding rule establishing that the police can stop someone for one reason even if they really hope to find evidence of something else. If the cops stop you for driving with a busted tail light but they secret hope to catch you with cocaine, you cannot challenge your drug bust in court on the grounds that the cops’ original reason for stopping you was based on a pretext. So long as they are allowed to stop you for the busted tail light, they can arrest you on any lawful grounds they discover during the course of that stop.
Today, the Supreme Court extended this rule to so-called “material witness” warrants. Federal law authorizes judges to “order the arrest of [a] person” whose testimony “is material in a criminal proceeding . . . if it is shown that it may become impracticable to secure the presence of the person by subpoena.” Invoking this law, former Attorney General John Ashcroft allegedly detained a man named Abdullah al-Kidd under false pretenses:
The complaint alleges that, in the aftermath of the September 11 terrorist attacks, Ashcroft authorized federal prosecutors and law enforcement officials to use the material-witness statute to detain individuals with suspected ties to terrorist organizations. It is alleged that federal officials had no intention of calling most of these individuals as witnesses, and that they were detained, at Ashcroft’s direction, because federal officials suspected them of supporting terrorism but lacked sufficient evidence to charge them with a crime.
It is alleged that this pretextual detention policy led to the material-witness arrest of al-Kidd, a native-born United States citizen. FBI agents apprehended him in March 2003 as he checked in for a flight to Saudi Arabia.Two days earlier, federal officials had informed a Magistrate Judge that, if al-Kidd boarded his flight, they believed information “crucial” to the prosecution of Sami Omar al-Hussayen would be lost. Al-Kidd re-mained in federal custody for 16 days and on supervised release until al-Hussayen’s trial concluded 14 months later. Prosecutors never called him as a witness.
Today’s decision holds that “an objectively reasonable arrest and detention of a material witness pursuant to a validly obtained warrant cannot be challenged as unconstitutional on the basis of allegations that the arresting authority had an improper motive.” In other words, if Ashcroft could legally detain al-Kidd as a material witness, it does not matter if the former attorney general had a nefarious reason for doing so.
Interestingly, Justice Kennedy, joined by Justices Ginsburg, Breyer and Sotomayor, filed a concurring opinion questioning whether Ashcroft did indeed have the legal authority to declare al-Kidd a material witness in the first place. Because Justice Kagan was recused, it is possible that she could provide the key fifth vote in a later case to limit law enforcement’s authority under the material witness statute.