The late night comics are turning serious, moved by the brutal murders of the French cartoonists, guys just like them.
Jon Stewart said, "They were killed for their cartoons."
Conan O'Brien said on his show, "All of us are terribly sad for the families of the victims, for the people of France, and for anyone in the world tonight who now has to think twice before making a joke."
On Jimmy Kimmel's show, Bill Maher said he takes the attack personally.
"We should be able to insult whatever we want. That is what free speech is like," said Maher.
Large gatherings in the USA paid tribute to the slain humorists who worked for the satirical magazine Charlie Hebdo. They held signs reading: "Je Suis Charlie," translating to, "I am Charlie."
In Paris, huge crowds marched defiantly proclaiming: "Not afraid."
Heavily armed police searched the French countryside for the wanted terrorists police say were responsible for the attack: Said Kouachi and his brother Cherif Koucahi.
Cherif appears in a 2005 French TV documentary when he was an aspiring rapper.
When the brothers forced their way into the Charlie Hebdo offices at 11:30 a.m., they found the staff at the morning editiorial meeting. The gunmen called out specific editors and cartoonists by name and shot them execution style.
Jean Cabut was a reknowned cartoonist. Bernard Verlhac and Georges Wolinski were also veteran satirists.
The death toll reached 12.
Analysts say the brothers must have received military training somewhere. They were wearing special gloves to steady their aim.
NYPD counter - terrorism Chief John Miller said at a press conference, "Conduct themselves in a way that indicates that they have either been trained for this or have operated in a war zone somewhere else in the world before."
A tight precise cluster of bullet holes in a police car windshield is another indication of training.
Connecticut students Nicole Keklik, LeAnne Walter and Jessica Sola are in Paris for a two-study program. They were told to stay on lockdown in the immediate aftermath of the shootings.
Sola told INSIDE EDITION, "We were advised to stay off the streets, stay off the metro, stay out of any highly-populated area. So, we just followed instructions and we waited to hear more."
Hear More From Nicole, LeAnne and Jessica.
The surviving staff at Charlie Hebdo vow that they will not be silenced. They plan to publish the magazine next week on schedule.