As authorities investigated the shooting Sunday that left 50 people dead, President Obama and other advocates for gun control made calls for stricter laws governing gun ownership.

In statements made Sunday afternoon, President Obama called the shooting “a further reminder of how easy it is for someone to get their hands on a weapon that lets them shoot people in a school, or a house of worship, or a movie theater, or a nightclub.”

He reiterated a need for stricter gun laws, saying, “To actively do nothing is a decision as well,” but didn’t elaborate on type of changes he would like to see. In the past, Mr. Obama has called for stricter background checks on gun purchases and for more research on technology to make guns safer, among other measures.

Florida has some of the friendliest laws for gun owners in the nation. The state imposes no restrictions on the design or magazine capacity of the AR-15 and other modern semiautomatic rifles of the type officials say was wielded by the suspected gunman, Omar S. Mateen.