A suspect in last Thursday’s Staten Island murders of a woman and her adult son was arrested Monday night in Pennsylvania, law-enforcement sources told The Post.

Anthony Morales, 49, of Staten Island, was critically wounded during the arrest by the NYPD and US Marshals. A gun was recovered at the scene, the sources said.

Adele and Anthony Rivera, 47 and 21, were shot outside the Mariners Harbor Houses.