EDISON - President Barack Obama lead the nation in a moment of silence this morning to honor Congresswoman Gabrielle Giffords and the others injured or killed in the mass shooting.

A grandmother from New Jersey was among the victims killed in the shooting. Phyllis Schneck, 79, lived in Rockaway and spent her winters in Tuscon.

Giffords, who was shot in the head Saturday, remains in intensive care at a Tucson hospital. Doctors say they're hopeful because she is responding to commands.

Giffords' husband, shuttle commander Mark Kelly, said in a statement that he expressed gratitude for the outpouring of support the family has received from Arizona and around the nation, and thanked medical and law enforcement personnel and others who have helped.

An Arizona sheriff says the 22-year-old man accused of killing the six people and trying to assassinate Rep. Giffords in Tucson is not cooperating with investigators.

Pima County Sheriff Clarence Dupnik told ABC's "Good Morning America" Monday that Jared Loughner had said "not a word."

AP wire services contributed to this report.