The widow of the NYPD cop killed in the Park Avenue mass shooting has given birth to the couple’s third son — naming him “Most Merciful’’ in Arabic, officials and sources said. Slain NYPD Officer Didarul Islam’s wife,

The wife of an NYPD detective who was killed in a mass shooting at 345 Park Ave. last month gave birth to their third child late Sunday night, officials said. Jamila Akhter gave birth to a healthy baby boy,