HARTFORD, Conn. (AP) Parents of the Newtown school shooting victims say they're frustrated with the opposition to gun control proposals prompted by the massacre and are calling on Congress to act.

One parent has even invited the head of the National Rifle Association to her home on Easter weekend to try to reach middle ground. Nelba Marquez-Greene's 6-year-old daughter Ana was among 20 first-graders and six educators killed at Sandy Hook Elementary School in December.

Neil Heslin was among several parents of children killed in the shootings who joined Vice President Joe Biden and New York City Mayor Michael Bloomberg in Manhattan on Thursday to call on Congress to pass an assault weapons ban and other measures.

Heslin says he's ashamed that Congress ``doesn't have the guts'' to pass gun control measures.