RIVERHEAD, N.Y. (CBSNewYork/AP) — A Long Island man was arraigned Friday in the beating of his mother in the same house where his brother was found dead.

Charles Okonkwo Jr., 18, of Dix Hills, pleaded not guilty Friday to one count of assault. A judge ordered a psychiatric exam.

Authorities said he attacked his mother, Chinwe Okonkwo, 52, in their home July 19. The woman remained in a coma at Stony Brook University Hospital with facial fractures as of Friday.

The Suffolk County District Attorney’s office said Friday that an investigation was ongoing into the death of Charles Okonkwo Jr.’s 15-year-old brother, Bradley Oknokwo. A prosecutor said in court additional charges were possible.

Authorities said Charles Okonkwo Jr. admitted late last month to hurting his mother and brother, WCBS 880 Long Island Bureau Chief Mike Xirinachs reported.

Police were called to the family’s Dix Hills home on the night of Saturday, July 19. The boys’ father, Charles Okonkwo Sr., 62, said he had just returned to his home at 3 Norman Ct. following a hospital stay when he discovered his son was dead and his wife had suffered severe injuries, police said. The younger Charles Okonkwo had fled the scene in a green 2002 BMW X5, but police later located him a short distance from the home.

The teen’s attorney did not immediately return a call for comment. He previously called the case “complicated.”

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