Jennifer Flynn Walker was arrested by Capitol Police in 2017 for sitting on the floor outside a U.S. senator’s office, she said, yelling about how her sister with Down syndrome depended on Medicaid. The 49-year-old health-care activist, who has organized dozens of protests at the U.S. Capitol, said she has witnessed officers pull peaceful protesters out of wheelchairs, arrest praying clergy and round up tearful women sharing stories of sexual assault.

“Using jazz hands gets you arrested,” said Flynn Walker, who has been arrested several times at rallies to protect the Affordable Care Act. “Yelling in the halls gets you arrested. Holding a poster gets you arrested. . . . It looks like the Capitol Police choose who to be aggressive with, and on Wednesday, they were not aggressive with people who were committing true acts of terror.”

Flynn Walker was among several people interviewed by The Washington Post who said their experiences being detained or arrested by Capitol Police at peaceful protests have contrasted sharply with the agency’s response to the mayhem wrought by a pro-Trump mob. Rioters, who mostly were White men, charged into the Capitol on Wednesday, roaming hallways, some vandalizing and looting, and forcing lawmakers to duck for cover and evacuate. Five people died, including a Trump supporter who was shot and an officer injured at the Capitol.

U.S. Capitol Police Chief Steven Sund defended his officers Thursday, saying they “responded valiantly when faced with thousands of individuals involved in violent riotous actions as they stormed the United States Capitol Building.” He later announced his resignation.

The Capitol Police arrested only 14 people on Wednesday, despite the unprecedented security breach. Ten were arrested for unlawful entry and another four for assaulting police officers or carrying weapons. D.C. police had arrested an additional 69 people as of early Thursday, most on curfew and unlawful entry charges. Law enforcement officials have vowed more arrests in coming weeks.

The mild law enforcement response to one of the most violent episodes in Capitol history appears at odds with the Capitol Police’s record of arresting suspects by the handful for far more minor crimes on most days, and on occasion, arresting hundreds of people in a single day.

The Capitol Police reported 525 arrests from the start of 2020 through the day before the Jan. 6 riot, according to a Post analysis of weekly summaries the agency posted online. Most were for nonviolent offenses. While the logs show that hundreds were arrested for traffic infractions, during that time frame, more than 300 were cited for illegally entering or creating disturbances while on the Capitol grounds or inside the Capitol or adjacent congressional office buildings.

Just two days before the riot, someone was arrested for allegedly attempting to enter the Cannon House Office Building, which is closed to the public due to the coronavirus pandemic, records show.

Among the other reported incidents over the past year that led to arrests: shaking a fence barrier with enough force to knock an officer backward, chanting on the Capitol Rotunda steps and playing the guitar in a Senate office building. One man was arrested for allegedly wearing tape over his mouth and holding up a sign at the Capitol Visitor Center, a violation of the District of Columbia’s code, which prohibits disorderly conduct in or around federally owned public grounds.

The weekly reports do not identify those arrested by name, state whether they were held in jail, or describe the outcome of the cases. Those arrested for minor infractions can pay a “post and forfeit” fine on the day of their arrest and not appear in court, court records show.

Peaceful protests are a common occurrence at the Capitol and routinely result in arrests. Actress Jane Fonda, now 83, was surrounded by a phalanx of officers and arrested several times during protests over climate change in 2019 and 2020. The newly elected Democratic senator from Georgia, the Rev. Raphael Warnock, was arrested in 2017 after singing and praying in the rotunda of a Senate office building with a group rallying behind the Affordable Care Act.

Rebecca Kling said she was arrested with 17 other Jewish activists in white T-shirts who held a brief sit-in in the Cannon Building in 2019. They chanted and sang songs such as “Oseh Shalom,” the Jewish prayer for peace, to demonstrate against the Trump administration’s immigration policies. Officers restrained their hands behind their backs with zip ties and loaded them into a van that took them to Capitol Police headquarters, Kling said. Like Fonda and Warnock, Kling paid a $50 fine to resolve the “crowding, obstructing and incommoding” charge under the District of Columbia code, court records show.

“My experience and all of the civil unrest in 2020 seems to indicate that if you are protesting for social justice, for Black Lives Matter, for immigrant kids kept in cages, you risk arrest and violence, but if you are carrying a Confederate or Trump flag you can walk right into the Capitol,” said Kling, 36, who lives in Chicago.

Savannah Junes, who is an Ohkay Owingeh Pueblo Indian, went to the Capitol with her mother in 2017 to pay homage to the statue of Po’pay, who led the 1680 Pueblo revolt against Spanish colonial rule. They sprinkled a handful of cornmeal on the feet of the statue, she said, a sign of respect for the dead among some Native Americans.

Capitol Police demanded their driver’s licenses, she said, asked a curator to inspect the statue for any damage and detained them for about an hour. They were not arrested but felt shaken by the experience.

“How can these armed White Trump supporters storm the Capitol building and have the police do absolutely nothing to stop them, and yet two Pueblo women prayed to a statue and we were effectively detained and thrown out?” Junes demanded. “It’s definitely a very, very clear picture of White privilege.”

Laughing loudly during former attorney general Jeff Sessions’s confirmation hearing in 2018 was enough to get a woman arrested by Capitol Police and convicted on two misdemeanor counts of unlawful conduct on Capitol grounds by a jury. A judge later threw out the convictions, saying that she should not have been tried for laughing.

Others who have interacted with Capitol Police said they behaved professionally. Indiana University professor Marc Lame, who said he was arrested on the Capitol steps along with about 150 others during a climate change protest last year, said they were allowed to chant and hold up signs for an hour before police told them to leave.

“We were disobeying lawful orders in an orderly way. That’s what they expected,” Lame said. But on Wednesday, he said, “They were overwhelmed with people who were disorderly and, in fact, violent.”

The Capitol Police are overseen by Congress and are exempt from accountability measures such as the Freedom of Information Act, the landmark public records law. The force also does not have to release watchdog reports from its inspector general, congressional documents show.

The agency agreed to post weekly arrest summaries after roughly 300 people were arrested in October 2018 protesting the Supreme Court nomination of Justice Brett M. Kavanaugh.

In the text of the 2021 budget bill, lawmakers “encourage” the Capitol Police to develop a more user-friendly process for sharing information with the public. The spending plan includes about $515 million for the agency, up from $464 million the previous year.

“The police are not transparent, so we have no idea how they’ve been preparing for these events,” said Amelia Strauss, a policy adviser for the progressive advocacy group Demand Progress, which tracks arrests by Capitol Police. “What we do know is they have abundant resources to respond to such a situation.”

The agency employs more than 2,300 people and has carried out a number of mass arrests in recent years. In the spring of 2016, more than 400 people — many of whom had participated in a 10-day march from Philadelphia — were arrested in one day while protesting the influence of money on politics. Nearly 600 people, mostly women, were arrested two years later while protesting immigration policy in the Hart Senate Office Building.

About one week before the mass arrests related to Kavanaugh, Sarah Remes of Washington, D.C., said she was arrested by Capitol Police for “incommoding” — obstructing a public space — with dozens of others who knelt in front of the Supreme Court in protest of Kavanaugh’s nomination.

“Maybe they only know how to deal with peaceful protesters?’’ she said she wondered as she watched Wednesday’s riot unfold on television. “Maybe they don’t know how to deal with violence?”

Kathy Beynette, 68, an artist in Leesburg, Va., said she was arrested during Trump’s impeachment hearings one year ago for singing on the Capitol steps and earlier during his term for making “jazz hands” at a health-care rally. Both times, she was taken to police headquarters, charged with incommoding and fined $50.

“These guys can bring gallows with nooses and flags on poles,” she said, “and we can’t bring our little signs that say, ‘Give Peace a Chance’ on a stick.”

Andrew Ba Tran contributed to this report.