Virginia Beach mass shooting reignites debate about silencers The mass shooting in Virginia Beach that left 12 people dead has reignited the debate about silencers. The gunman used at least one .45-caliber pistol with a suppressor. CBS News' Errol Barnett has the latest on the investigation, and then retired ATF agent David Chipman, a senior policy advisor at Giffords, joins CBSN to discuss whether the devices can make a mass shooting more lethal.