At least 59 people were killed and more than 525 wounded in Las Vegas last night when a 64-year-old man opened fire from the 32nd floor of the Mandalay Bay hotel onto the crowd below at a country music festival.
Police have found 23 guns in shooter Stephen Paddock's his hotel room, as well as "in excess of" 19 firearms and explosives at his Nevada home.
But as yet, no clear reason for the killings has emerged.
Las Vegas Sheriff Joe Lombardo has described the shooting as a "lone wolf" attack.
Mr Brown told Checkpoint with John Campbell it was a constitutional right in the United States to bear arms and that was very important.
But he said that right has to be balanced with protecting people's right to live.
"Are there people who have guns illegally that shouldn't have them? Absolutely, take them away, throw them in jail, don't pass go, don't collect $200.
"But to take away the ownership rights of law-abiding citizens like me and others who treat and respect the second amendment and the right to carry and bear arms, and the sanctity of life?
"I think that's inappropriate."
Mr Brown said the National Rifle Association gun lobby helped fund his campaigns when he was a US senator and in one campaign gave him $US42,000.
But he said when he saw these types of gun attacks it destroyed his heart.
"I'm not sure what the answer is I'll be honest with you, I don't."
This article was originally published by RNZ.