More than 400 people have been arrested following a demonstration at Washington's Capitol Hill.
Police said those arrested had been acting "unlawfully" by staging the mass sit-in.
Organised by the group 'Democracy Spring' the demonstration was reportedly set up "to demand Congress take immediate action to end the corruption of big money in our politics and ensure free and fair elections."
The sister of Miriam Carey, the 34-year-old mother shot dead by police after trying to ram her car through a White House barrier said there was "no need for a gun to be used."
Speaking outside her home in Brooklyn, retired NYPD officer Valarie Carey said there was a police protocol to deal with people suffering from postnatal depression that should have been followed, and that she did not understand why her sister was shot when she was unarmed.
Miriam Carey, the 34-year-old woman shot dead following a dramatic car chase through the streets of Washington, suffered from post-natal depression, her sisters said, confirming what her mother said.
Amy Carey-Jones confirmed her sister had been on medication to help with her postnatal depression, and had endured psychotic episodes.
She said her sister's illness did not impact her loving personality, and said the family had a lot of serious questions over why she was shot dead. Speaking to reporters, alongside her sister Valarie, she said:
"We do not have answers about why they did what they did. They felt she was some particular threat, but Miriam was not firing any shots, there were no weapons, so we are still very confused as a family as to why she is not alive."
"Unfortunately, if people do have moments of crisis, if people do have moments of instability, how do people protect that person? How do they help? How do they operate in a way that contains the situation?"
The woman killed after a car chase near the White House in Washington DC was delusional and believed President Obama communicated with her, the Associated Press has reported, citing an official.
The mother of a woman who was shot dead after driving erratically near the White House has said that her daughter suffered from postnatal depression, ABC News reports.
Idella Carey said her daughter, Miriam Carey, suffered from the condition after the birth of her daughter last August, and that she had been "hospitalised".
Postnatal depression is a form of clinical depression that affects mothers after birth.
The 18-month-old child who was in the car during a chase near the White House was not injured and has been placed with child protective services.
NBC News cites law enforcement sources as saying that the child is believed to be the driver's daughter.
Police and FBI officials have descended on an apartment building in Stamford, Connecticut where the driver lived.
Teams wearing hazardous materials suits appeared to be preparing to enter the building and bomb squad truck was seen driving to the area.
Residents said they had been evacuated shortly after 5pm local time (10pm UK time).
Relatives of the driver killed in a chase near the White House have told police that she had mental health issues, NBC News reports citing a senior law enforcement official.
Miriam Carey, 34, is said to have had a fall a couple of years ago leading to the issues.
Carey's employer corroborated that she had suffered a fall, and that she had returned to work pregnant.