Not long after we met, Aaron Alexis, 34, of Fort Worth, Texas, shot dead 12 people at a naval installation in Washington DC before being shot and killed in a shoot-out with police.
On that evening's show, Morgan let fly: "I just boil over when I hear these gun lobbyists calmly insisting the only answer is more guns, when that just clearly makes the situation even worse. I despair for America ... The gun debate is so entrenched on either side I fear nothing will ever get done."
Morgan describes the Washington shootings as "another terrifying illustration of America's hideous gun violence epidemic".
"A hundred thousand Americans are hit by gunfire each year, 30,000 kill themselves with guns, and 12,000 are murdered by guns. If a new disease took that kind of toll, they'd spend billions fighting it."
He advocates a three-pronged approach: universal background checks for all gun purchases; a ban on assault weapons; and limiting all magazines to 10 bullets."This won't stop all gun violence, but it will help reduce the volume and scale of these massacres.
"The politicians have been cowed into silence by the National Rifle Association ... Until enough Americans rise up to say 'enough' on guns, the slaughter will continue, and the NRA will continue to say the only answer to gun deaths is more guns, which is palpably absurd, and purely designed to make more money for their gun-manufacturer donors."
Despite receiving death threats for his criticism of gun control laws and, last December, prompting more than 100,000 Americans to sign a petition calling for his deportation - to which the White House issued an official response - Morgan says he loves his adopted country.
He's frustrated that Americans are "so blind to this terrible, and worsening blight on their society".
"There are many issues at play here - mental health and violent video games being two important ones. But the real villain is the gun. Other countries have the same issues but no guns, and they don't have the gun murders. It's a simple equation."
This crusader is the same man who admits in his memoirs to "trashing people's lives" as editor of the News of the World. "It was a pretty moral-maze journey I went on as a young person, thrust into the maelstrom of editing at 28 - the youngest-ever Sunday editor - and then on to the Mirror at 30 ... You do stuff you think was wrong, you target people unfairly."