(The Hill) — Democratic gubernatorial candidate Beto O’Rourke on Wednesday responded at a heckler who laughed as he discussed a recent mass shooting.

O’Rourke, who has expressed outrage after a gunman opened fire inside an Uvalde, Texas, elementary school and killed 19 children and two adults, delivered a speech at a town hall in the city of Mineral Wells.

While discussing some details of the tragedy, somebody in the crowd laughed, prompting O’Rourke to swiftly turn around.

“It may be funny to you, motherf—–,” he said, “but it’s not funny to me.”

O’Rourke earned a round of applause from the crowd for the response.

The Democratic candidate, who has pushed for more restrictive gun laws, will face off against GOP Gov. Greg Abbott in November.