The 26-year-old son of a retired Manhattan Supreme Court judge fatally bludgeoned his mother with a piece of furniture at the family’s posh Upper East Side co-op Tuesday and then jumped 16 floors to his death, police and law enforcement sources said.

Doug Solomon, 26, was found naked and bleeding in the courtyard of the East 79th Street building around 10:30 a.m. after the rage-fueled attack and was heard screaming on his way down, cops and witnesses said. 

“It was the loudest thud. At first I thought it was an air conditioning unit,” a resident of the building who declined to share his name told The Post.

“I looked down and he was right below my window … he was butt naked.” 

Solomon’s mother, Diane Gallagher, 65, was found dead in an apartment bedroom with head trauma after her son beat her with a piece of furniture, law enforcement sources said.