Democratic Rep. Ted Lieu (Calif.) walked out of a moment of silence being held on the House floor on Monday for the victims of Sunday’s mass church shooting in Texas.

After Lieu left, he took to Facebook to explain his actions, saying he “can’t do this again,” The Hill reported. Democrats have been critical of Republicans for expressing “thoughts and prayers” and conducting moments of silence for the victims of gun violence, saying they should take action in the form of gun control legislation.

“My colleagues right now are doing a moment of silence in the House of Representatives’ chambers,” Lieu said. “I respect their right to do that and I myself have participated in many of them, but I can’t do this again.”

Lieu referenced “three of the worst mass shootings in U.S. history” as he called for stricter gun regulation.

“We need action,” Lieu said. “We need to pass gun safety legislation now.”

He urged his colleagues to pass a “universal background check law” and a ban on “assault rifles” and “bump stocks.”

“We need to do that. We cannot be silent. We need to act now,” he said.

The Air Force announced Monday it failed to share the records of the shooter that would have prevented him from purchasing a firearm due to a 2012 domestic-violence-related court-martial while serving.