A Southern California man who was arrested on an explosives charge after a blast killed his former girlfriend last week at her day spa is scheduled to appear in court.

Fifty-nine-year-old Stephen Beal is set to appear in federal court in Santa Ana Monday afternoon.

Beal is charged with possessing an unregistered destructive device that the FBI says was found at his home.

He has not been charged with the blast that killed 48-year-old Ildiko Krajnyak (IL-di-koh KRY-nyak) on May 15 when she opened up a cardboard box at the spa in the city of Aliso Viejo south of Los Angeles.

Beal and Krajnyak dated until recently and remained business partners.

Beal did not enter a plea during a court appearance last week and his public defender would not comment.