*Editor's note: This story has been updated throughout.
Texas' top elected officials on Monday offered an absolute defense of free speech in the wake of a Garland shooting that left two gunmen dead outside a contest featuring cartoons of the Prophet Muhammad.
Speaking with reporters Monday morning, Gov. Greg Abbott called the shooting a "heinous crime" that struck at the heart of the First Amendment. He added he would not feel differently if the shooting had happened in connection with an event mocking Christianity.
"What Christians believe is we need to protect our religious liberties, but that doesn't mean engaging in gun battle to do so," Abbott told reporters following the annual National Day of Prayer breakfast in North Austin. In a statement late Sunday, Abbott said Texas officials were investigating the shooting.
On Monday morning, Lt. Gov. Dan Patrick agreed with Abbott that the events like the one held Sunday provide "no excuse for violence."
"If Americans are threatened to be killed for their words & actions, no matter how offensive, then freedom itself is lost and with it America is lost," Patrick wrote on Facebook.
As the event in the Dallas suburb was winding down Sunday evening, the gunmen — armed with body armor and assault rifles — drove to the front of the venue and opened fire on a security guard, according to police officials. A Garland police officer returned fire, shooting and killing the men. The security guard's injuries were not life-threatening.
A bomb squad stayed on the scene late into the night, though no bombs were ultimately found inside the vehicle driven by the gunmen, Garland police spokesman Joe Harn said Monday morning. He cautioned that the investigation into the shooting would be slow-going.
At a news conference in Garland that was livestreamed on the WFAA website, Harn said authorities were not ruling out the possibility the shooting was a terrorist attack.
"We're certainly looking into that," he told reporters. "We have not knocked that out."
There was not much official information about the gunmen available Monday. ABC News identified one of the gunmen as an Arizona man who had previously been investigated for terrorism. The Washington Post reported the second gunman was the Arizona man's roommate.
Harn, however, said Monday morning that authorities would not be releasing any names.
Abbott has asked Steve McCraw, director of the Texas Department of Public Safety, to "fully investigate the assailants' ties to organized terrorist activity," according to the governor's office. Abbott received a briefing from McCraw on Monday morning. The governor also called and offered his support to Garland Mayor Douglas Athas and Bruce Joiner, the Garland ISD security officer shot by the gunmen.
Less than two hours before the shooting, about 200 people had gathered inside the Curtis Culwell Center to vie for a $10,000 award for the best drawing of Muhammad. Depictions of the prophet are offensive to many Muslims and have led to deadly violence around the world.
Organizers had defended the contest as an expression of free speech. Some said it was in response to a pro-Islam rally earlier this year in Garland that came just days after a deadly attack on a satirical newspaper in Paris that published caricatures of Muhammad.
Police officials said they were on high alert given the controversial nature of Sunday's contest. The New York-based American Freedom Defense Initiative, which hosted the event, shelled out $10,000 on extra security.
Texas lawmakers avoided directly commenting on the contest Monday but categorically defended the organizers' right to hold it.
"Quite simply, an attack on free speech is an attack on all Americans," U.S. Sen. John Cornyn, R-Texas, said in a statement.
"Freedom of expression has again been attacked by fanatics," U.S. Rep. Michael McCaul, R-Austin, said in a statement that drew a comparison between the "capitals of Europe" — the sites of recent attacks fueled by radical Islam — and the "streets of Garland."
Other politicians said they were waiting to see all the facts come out. U.S. Sen. Ted Cruz, the Texas Republican running for president, said on social media he was grateful for authorities who responded to the attack and will "continue to monitor the situation closely."
State Sen. Don Huffines, the Dallas Republican whose district includes the site of the shooting, said in a statement he was "saddened at the senseless attack." "The use of violence on a community is never the right path," he added.
As the situation developed late Sunday, officials struck a cautious tone.
Asked if DPS was offering assistance or investigating the incident, McCraw told the Tribune, "Yes and that is all we can say."
On Twitter, Patrick wrote that his office was in touch with DPS. “Facts still unfolding,” he added.
Prominent conservative activist Katrina Pierson was among the attendees at the contest. Pierson recalled a relative calm as authorities worked to move attendees to a safe location.
"Everyone just sang and prayed and there was no chaos," said Pierson, a member of Patrick's Grassroots Advisory Board. "It was praying for the officer that was shot and praying for our country and praying for free speech."
Terri Langford and Alana Rocha contributed reporting.