A Saratoga Springs man has admitted to killing his former partner and mother of his child in exchange for a sentence of 23 years to life in prison. WNYT reports Sebastian Mabb pleaded guilty in Saratoga County Court on Thursday to second-degree murder in the death of Brianna Craig inside a home at Vanderbilt Terrace on Feb. 6. Craig was smothered with a pillow, according to law enforcement sources.