One of the victims was the great-granddaughter of Oregon Senator Jeff Merkley's first cousin, he said on Friday.
Many of the 20 presidential candidates joined in on the social media conversation.
A gunman on Thursday opened fire at Umpqua Community College in Roseburg, Oregon.
Colorado is home to gun-huggers and pot smokers, pro-lifers and atheists—but running for the middle ground.
"It's not enough for New York State to pass a gun law," the governor says.
Officers in states with the highest gun ownership are three times as likely to be killed compared to officers in states with the lowest.
Alison Parker and Adam Ward were fatally shot on live TV in Virginia on August 26.
Supporters want universal background checks for all firearms sales.
The measure marks a rare effort by a leading Republican lawmaker to curb gun purchases.
Dylann Roof is accused of fatally shooting nine people in Charleston last month.
The fast-food chain still won't allow customers to openly carry handguns, despite a new firearms law in Texas.
The study found a large drop only in killings involving guns, not in homicides carried out in other ways.
The Texas legislature has voted in favor of allowing guns inside buildings on college campuses in the Lone Star State.
Chris Martinez was one of six people killed by a gunman last May 23; his father has been busy ever since.
Oregon joins California, Colorado, Connecticut, Delaware, New York, Rhode Island and Washington.
Physicians say the law amounts to unacceptable interference by the government.
The judge said no evidence had been produced which showed limiting magazines to 15 rounds seriously diminished the ability to defend oneself