The federal government will seek the death penalty against Payton Gendron.
The Justice Department is scheduled to make that announcement this afternoon involving the mass shooting two years ago at a Buffalo supermarket, following Gendron's appearance in federal court.
The court filing has already been released.
Family members of the 10 people he killed at the Tops store have also been asked to be in court.
Gendron has already been sentenced to life in prison on state charges.
Gendron's lawyers have said he would plead guilty in the federal case if prosecutors agree NOT to seek the death penalty