[JURIST] The US Supreme Court [official website; JURIST news archive] on Monday ruled [opinion, PDF] in McDaniel v. Brown [Cornell LII backgrounder; JURIST report] that a federal district court may not consider non-record evidence when conducting a sufficiency review of evidence during federal habeas corpus proceedings. In a per curiam opinion, the Court found that the US Court of Appeals for the Ninth Circuit erred when it allowed consideration [opinion, PDF] of a report detailing statistical errors [NYT backgrounder] in DNA evidence against the defendant submitted 11 years after the trial as part of a habeas petition under the sufficiency-of-the-evidence standard announced in Jackson v. Virginia [opinion text].

We have stated before that "DNA testing can provide powerful new evidence unlike anything known before." … Given the persuasiveness of such evidence in the eyes of the jury, it is important that it be presented in a fair and reliable manner. The State acknowledges that [the prosecution witness] committed the prosecutor's fallacy … and the Mueller Report suggests that [the witness's] testimony may have been inaccurate regarding the likelihood of a match with one of respondent's brothers. Regardless, ample DNA and non-DNA evidence in the record adduced at trial supported the jury's guilty verdict under Jackson[.]

The Court noted that even if the Court of Appeals were permitted to consider the post-conviction report, it committed an "egregious" error by excluding all DNA evidence from sufficiency consideration.

Addressing the issue of post-conviction use of DNA evidence last June, the Court ruled [JURIST report] in District Attorney's Office v. Osborne [Cornell LII backgrounder] that a defendant does not have the right to obtain access to the state’s biological evidence in order to do DNA testing.