Sen. Marco Rubio (R-Fla.) is open to polices that would prevent criminals and the mentally ill from obtaining guns, his spokesman said on Monday.

Rubio has a B+ rating from the NRA and an A rating from the Gun Owners of America. 

“In the aftermath of the unspeakable tragedy in Newtown, Sen. Rubio, like millions of Americans, is looking for public policy changes that would prevent such a horrible event from happening again," Alex Conant, Rubio's communications director, said in a statement. "He remains a strong supporter of the Second Amendment right to safely and responsibly bear arms. But he has also always been open to measures that would keep guns out of the hands of criminals and the mentally ill. The challenge with gun laws is that by definition criminals do not follow the law. For example, Connecticut's gun laws, some of the strictest in the nation, were not able to prevent this atrocity. Nevertheless, he supports a serious and comprehensive study of our laws to find new and better ways to prevent any more mass shootings."

Florida's other senator, Democrat Bill Nelson, has voted to ban assault weapons in the past. 

Two Democratic senators with high rankings from the gun lobby said Monday in the wake of the Sandy Hook school shooting that they would support more regulation of assault  weapons.