FILE - In this July 7, 2015 file photo, Juan Francisco Lopez-Sanchez, right, is led into the courtroom by San Francisco Public Defender Jeff Adachi, left, and Assistant District Attorney Diana Garciaor, center, for his arraignment at the Hall of Justice in San Francisco. A judge on Friday, July 28, 2017, in San Francisco says a federal agency has agreed to allow a ranger to testify at the trial of Lopez-Sanchez, the Mexican native charged with the 2015 shooting death of a San Francisco woman with the ranger's gun that has become a flashpoint in the national immigration debate. (Michael Macor/San Francisco Chronicle via AP, Pool, File)