Sen. Charles Schumer announced plans Sunday to push for stricter gun control laws, citing the recent deadly shootings of nine people in a South Carolina church.

Schumer, author of the Brady Law requiring background checks for gun buyers, said he wants to expand the "weak" laws on federal background checks, saying they let people who shouldn't have a gun get them anyway.

Though he acknowledged it was unclear if stricter laws would have prevented 21-year-old Dylann Roof from allegedly shooting up Emanuel African Methodist Episcopal Church in Charleston on June 17, he said, "If we toughened up the law on guns, there would be many fewer of these massacres," also pointing to the recent mass shootings in Aurora, Colorado, Newtown, Connecticut, and Virginia Tech.

"I do hope and think that the horror in South Carolina will serve as a wake-up call," Schumer said.

The senator committed to closing a loophole that allows buyers to avoid background checks by purchasing guns online or at gun shows, placing blame on the National Rifle Association for making it harder to track gun sales.

"It's almost impossible to find them because the NRA has put laws on the books that make it hard to trace where guns come from," he said.

The NRA did not return a request for comment.

Schumer said he has spoken with senators from both parties who expressed interest in working with him, but would not name them.