A Massachusetts man was arrested Tuesday on gun charges after he was found with a pistol in his waistband soon after touring the US Capitol building in Washington, D.C., police said.

The U.S. Secret Service and Washington, D.C. Metropolitan Police Department originally spoke to the man in a hotel on Tuesday morning. ABC reports they were responding to an alert from the Carlisle Police Department about a man with a gun who had expressed suicidal ideations on social media and was headed to Washington.