WASHINGTON — A woman whose Chicago police officer brother was fatally shot in 2010 says it's time for Congress to pass laws keeping guns from criminals. Another woman says firearms restrictions prevented her from protecting her parents when they were killed in a 1991 mass shooting in a Texas restaurant.

The two were among several witnesses taking opposing sides Tuesday as the Senate holds its second hearing on gun curbs since December's shooting deaths of 20 first-graders in Newtown, Conn. This time, a Senate Judiciary subcommittee is examining the constitutionality and effectiveness of federal firearms limits.

"We need to keep guns out of the hands of criminals and those who are mentally unstable," the subcommittee's chairman, Sen. Richard Durbin, D-Ill., said in a brief interview Monday. "I hope everyone will acknowledge that within our Constitution is not only an individual right to bear arms, but the collective right of Americans to be safe."