A man who police say fatally stabbed his ex-girlfriend inside a mall in upstate New York has pleaded not guilty to murder.

Prosecutors say 43-year-old Keith Sparks attacked Mallicia Tipps inside the Sears store at the McKinley Mall in suburban Buffalo about 2 p.m. Wednesday.

Sparks was arrested later that night at his Niagara Falls home.

He is being held without bail after appearing Thursday in Hamburg Town Court. He's due back for a felony hearing Oct. 1. It's unclear if he has a lawyer.

Hamburg Police say Sparks apparently followed Tipps' vehicle to the mall and chased Tipps and her friend from the parking lot into the store where he stabbed her several times. The 38-year-old victim died at the scene.