Cornyn's Line of Duty Act, S. 698, would allow judges, prosecutors and law enforcement officials at the state and federal levels to carry firearms into federal courtrooms and other federal buildings where weapons are not normally allowed.

It also lets these officials use ammunition magazines "of any size," according to a description of the bill from Cornyn's office.

The legislation would allow state and local governments to use existing federal funding to provide security details for prosecutors and judges who are in danger of retaliation. And it creates new federal penalties for killing or attempting to kill these officials.

"This legislation would provide prosecutors, judges, and law enforcement officials more flexibility in how they choose to protect themselves and their families, as well as create stronger offenses for those who target our public officials," Cornyn said.

Investigators suspect that members of the Aryan Brotherhood murdered District Attorney Mike McLelland and his wife, Cynthia, which has already prompted a federal prosecutor in Texas to drop out of an ongoing case against the group.