When a group of Cub Scouts met with a Colorado state senator this month, they asked her about some of the most controversial topics in the nation: gun control, the environment, race and the proposed border wall between the United States and Mexico.

But questions from one Cub Scout, Ames Mayfield, 11, got him kicked out of his den in Broomfield, Colo., according to his mother, Lori Mayfield. At the meeting on Oct. 9, for which the scouts were told to prepare questions for State Senator Vicki Marble, Ms. Mayfield recorded her son asking the senator why she would not support “common-sense gun laws.”

“I was shocked that you co-sponsored a bill to allow domestic violence offenders to continue to own a gun,” Ames said in a question that took more than two minutes. He continued, “Why on earth would you want somebody who beats their wife to have access to a gun?”

The event took place not long after the Las Vegas shooting. As part of her answer, Ms. Marble, a Republican from Fort Collins, defended her position on gun ownership, saying that shootings in Las Vegas and Aurora, Colo., happened in so-called gun-free zones, and that “the more guns a society has, the less crime or murders are committed.”