On February 20, 2024 the Supreme Judicial Court issued an important decision in Commonwealth v. Arrington regarding "black box" algorithmic digital forensics. The prosecution tried to use iPhone "frequent location history" evidence to prove the defendant’s presence at the scene. Agreeing with arguments made by a large amicus coalition including MACDL represented by Attorney Wood, the SJC excluded the evidence. We were pleased to see the SJC rely on Attorney Wood’s litigation in Commonwealth v. Rintala to require that new, unusual expert testimony be excluded unless the Commonwealth can prove how the underlying technology worked and that it is reliable and testable.
Amicus: Exclude Expert Testimony on Proprietary "Black Box" Technologies
Attorney Wood - on behalf of MACDL and in cooperation with a team from the Electronic Frontier Foundation, the ACLU, and NACDL - recently filed an amicus brief with the Supreme Judicial Court arguing that supposed expert testimony regarding proprietary “black box” technologies should be excluded. Such testimony does not pass Daubert/Lanigan test unless accompanied by testimony from an expert who knows what is in that black box! Here, a prosecution witness intended to testify regarding the defendant’s iPhone “frequent location history” without knowing anything about the algorithm that produces such a history, including the reliability of the data it uses or the reliability of the algorithm used to reach the supposed result. The defendant’s attorney successfully argued below that the testimony failed Daubert/Lanigan. The SJC should uphold that order.