WASHINGTON (AP) — Three days before the pro-President Donald Trump riot at the Capitol, the Pentagon asked the U.S Capitol Police if it needed National Guard manpower.

And as the mob descended on the building Wednesday, Justice Department leaders reached out to offer up FBI agents.

The police turned them down both times, according to a defense official and two people familiar with the matter.

They told The Associated Press that the Capitol Police had planned for a free speech demonstration and didn’t need more help.

But the Capitol ended up being overrun.

The failure also raised questions about the treatment of mainly white Trump supporters, compared with the Black and brown protesters across the country who demonstrated last year over police brutality.

The head of the union representing U.S. Capitol Police is calling on the department’s chief to resign, saying the Capitol riot “should never have happened.”

Gus Papathanasiou said in a statement Thursday that a lack of planning led to officers exposed to violent protesters storming the Capitol. He says officers lacked the backup and equipment needed to control rioters and argues that Capitol Police Chief Steven Sund must be replaced to prevent similar incidents in the future.

Police have been criticized for not immediately arresting many people who stormed the Capitol. Papathanasiou said, “Once the breach of the Capitol building was inevitable, we prioritized lives over property, leading people to safety.”

Papathanasiou is chair of the U.S. Capitol Police Labor Committee.