A friend of the Bronx woman who was stabbed to death at St. Mary's Park allegedly by a cyber-stalker is warning women about the dangers of meeting people online.

Raymond Dennis, who police believe killed 23-year-old Nimzay Aponte Tuesday after he saw her with another man, pleaded not guilty to the murder charge, claiming he had a relationship with the woman. However, Aponte's friend Jessica Matthews says Dennis had been stalking the mother of two since December of last year.

"He said, 'if I can't have you, no one can,'" Matthews says of the suspect.

Matthews adds that Dennis constantly tracked Aponte's whereabouts and even stood outside Matthews' own window, ignoring her pleas to leave her alone.

Dennis is scheduled to appear in court next week on unrelated charges.