The man, described as a previous resident of Narberth, Pa., was unarmed and was detained without incident, police said.

The Internal Revenue Service (IRS) building stands on April 15, 2019 in Washington, DC. The Internal Revenue Service (IRS) building stands on April 15, 2019 in Washington, DC. Zach Gibson/Getty ...

WASHINGTON, DC - APRIL 05: People use IRS Direct File at the Internal Revenue Service Building on April 05, 2024 in Washington, DC. (Photo by Tasos Katopodis/Getty Images for Economic Security ...

FILE - A sign is displayed outside the Internal Revenue Service building on May 4, 2021, in Washington. (AP Photo/Patrick Semansky, File) FILE - A sign is displayed outside the Internal Revenue ...