Police are investigating the deaths of a married couple in Manhattan as a murder-suicide — after the husband allegedly stabbed his wife to death and then jumped out a window, cops and sources said Monday.

Cops responded to a 911 call around 10:20 p.m. Sunday for a report of a man who jumped from a building on Sherman Avenue near West 207th Street in Inwood.

When they arrived, they found Campo Elias Albuja-Montalvo, 72, sprawled out on the pavement in front of his building, police said.

Albuja-Montalvo’s wife, Francia Walsh, 78, was soon discovered on a sofa in the living room of the couple’s sixth-floor apartment with multiple stab wounds to her torso.

Sources at the scene said Albuja-Montalvo stabbed his wife, then slit his wrists and jumped out the sixth-story window. He bounced off the second-floor balcony and landed on the cement, where cops found him unconscious.

He was pronounced dead at the scene.

The pair was known around the neighborhood as having a volatile relationship, sources added.

Neighbor Miguel Alonso, 63, blinked back tears as he described them as a quiet, elderly couple who kept to themselves.

“I never thought this would happen,” Alonso said. “Aged people like that — it’s terrible.”

Police said they recovered a knife at the scene. Albuja-Montalvo did not leave a suicide note.