Now we're learning more about where law enforcement officers were, and where they weren't, while bullets were flying inside the building.
The sheriff said he was "devastated, sick to my stomach", over the deputy's inaction, the AP reported. "He never went in", Sheriff Israel said.
The First National Bank of Omaha has said it will not renew a contract with the National Rifle Association to issue a NRA-branded Visa card.
A new poll from Quinnipiac University, which is based just 30 miles from Sandy Hook Elementary School, found US support for gun control is at its highest level ever with more than 2-to-1 support and that 97 percent of respondents support universal background checks.
What did the officer do?
A Marjory Stoneman Douglas High School student who survived last week's shooting and her father appeared on "The Ingraham Angle" Thursday night to react to the revelation that an armed school resource deputy waited outside the school as the massacre unfolded.
The sheriff explained that even though Peterson arrived only 90 seconds after the first shot, the deputy "lingered" outside the building for a minimum of four minutes.
Trump says he supports fixing background check and mental health loopholes, raising the gun purchasing age for rifles to 21, and banning bump stocks - the device used by the Las Vegas shooter to increase the firing speed of his semi-automatic rifles.
Pep Guardiola charged by FA for wearing pro-Catalunya yellow ribbon
City's manager has been wearing the ribbon since December in support of imprisoned politicians and activists. I am only asking that people should be allowed to vote, let's not forget that.
Al-Shabaab attack in Mogadishu leaves at least 22 dead
According to local media, Somali-based insurgent group al-Shabaab has claimed responsibility for the attacks on Friday evening. Al Shabaab, an al Qaeda-linked terror group, has carried out several deadly vehicle bomb attacks in the city.
Did Zaza Pachulia intentionally fall on Russell Westbrook?
Pachulia then fell on top of the Thunder star, trapping his leg in an uncomfortable position. "Yes, for sure", said Westbook. Leonard missed the rest of the playoffs with a left ankle injury. "Nobody pushed him.
When asked what Peterson should have done, Israel said the deputy should have "went in, addressed the killer, killed the killer". He added that the video showed Mr Peterson doing "nothing".
The suspect, 19-year-old Nikolas Cruz, has been jailed on 17 counts of murder and has admitted the attack.
A tracker on the organization's website says there have been 338 violent incidents and threats impacting 438 schools across the nation since February 15, when the Florida shooting occurred.
There are between 14,000 and 20,000 such officers in the United States, according to the National Association of School Resource Officers.
Peterson had been stationed at the high school since 2009, and received numerous glowing performance reviews and evaluations from his superiors.
In recent days, NRA officials have lashed out at gun control advocates, arguing that Democratic elites are politicising the Parkland rampage to erode gun rights.
"Our schools are essentially gun-free zones and that makes them very risky places", the president said. "They hate individual freedom". The vast majority of Americans want to see some type of gun reform, including gun owners and Republicans who strongly support Second Amendment rights.
'Because I didn't know if we were going to make it out on the time, I didn't know what was going to happen next. "If there is wrongdoing on the part of our deputies, we'll handle it accordingly as I have for 5 years as sheriff". Speaking at The King Center in Atlanta, the Rev. Bernice King said tragedy "gives us an opportunity to lay aside for a moment our differences and really look at how we can come together as humanity and move forward with these injustices and these evils that continue to beset us". With 3.2 million teachers in public schools and 400,000 in private schools, it would mean preparing and arming 360,000 to 1.4 million educators.
"Anyone who wants guns in schools has no understanding of what goes on inside them - or worse, doesn't care", she said. Mr Trump has proposed paying bonuses to teachers and other staff with weapons training if they carry concealed guns in the classroom. Spitzer said the reaction was likely a reaction to the student mobilization that followed the Florida shooting, but he said it was too soon tell how significantly it will sway the country's wider gun debate. I've been to the homes where they're sitting shiva. Trump said the "evil massacre" of 17 people at a Florida high school last week had "broken our hearts".