“He was only stopped finally because he did not have a silencer on his weapon. And the sound drew people to the place where he was ultimately stopped. Can you imagine what this would have been if he had silencers on these weapons?”
— Sen. Tim Kaine (D-Va.), interview with The Washington Post, Oct. 2, 2017

...The Facts

First of all, there are relatively few reports of suppressors being used in crimes. In 2015, 125 suppressors were recovered from crime scenes where a trace was requested by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) — when nearly 265,000 pistols, revolvers, rifles and shotguns were recovered. The Violence Policy Center, which opposes the proposed law, argues that this shows the success of current restrictions. “The limited information available suggests that the current regulation of silencers under the NFA is working to keep criminal use of the devices rare,” the group says.

...Hearing damage begins to occur at about 85 decibels, which is the sound of a hairdryer. Various reports have indicated that the Las Vegas shooter had AR-15-type rifles. A 30-decibel reduction means an AR-15 rifle would have a noise equivalent of 132 decibels. That is considered equivalent to a gunshot or a jackhammer. A .22-caliber pistol would be 116 decibels, which is louder than a 100-watt car stereo. In all likelihood, the noise level is actually higher...

...But in any case, the evidence does not support Kaine’s claim that the shooter was “only stopped” because he did not have suppressors on his weapons. That’s exaggerated and could leave a misleading impression on people only familiar with silencers in the movies. The crowd under attack might have had trouble establishing the location of the shooter if he had silencers, but he fired from a hotel filled with guests who almost certainly would have heard 132 decibels from the floors above and below the attack.