During the standoff, police requested that Facebook deactivate her account on the service and on Instagram, which Facebook owns, Baltimore County police Chief Jim Johnson told reporters Tuesday.
The Facebook account, which allows live-streaming, was taken offline, but two 1-minute videos were still on her Instagram account as of Tuesday afternoon.
The videos were posted just before Korryn Shandawn Gaines, 23, was killed in an exchange of gunfire in which a 5-year-old boy was wounded in the arm.
In one video, a tactical officer appears in the doorway of an apartment. There is talking that is hard to discern but there is no apparent conversation between the officer and Gaines. The video has since been taken down.
In the other video, Gaines talks to the boy, who gives halting answers, which raises the possibility the boy might have been coached.
Gaines is heard asking the boy what the police are trying to do. He answers, "They're trying to kill us."
The boy is being treated for non-life threatening injuries at The Johns Hopkins Hospital in Baltimore, where he is in good condition, police said.
Responding to reporters' questions about whether police had deactivated Gaines' social media accounts during the standoff, Johnson said law enforcement has no power to deactivate an account.
Facebook has a portal for law enforcement requests, though, and police did ask the social media giant to deactivate her account "to preserve the integrity of the negotiations." Facebook complied, he said.
Gaines was posting video of the operation as some of her followers urged her not to follow police orders, Johnson said.
Gaines had shotgun, police say
Around 9:20 Monday morning, three warrant service officers went to serve a man and a woman in the Randallstown area of Baltimore County, Maryland.
Upon arriving, the officers heard the voices of a man, a woman and a crying child inside the apartment.
They waited outside the door for about 10 minutes, Johnson said. Then, one officer obtained a key to the apartment.
The man, Kareem Courtney, 39, was wanted on an assault warrant while Gaines was wanted on a bench warrant for failing to appear in court to face traffic charges, police said.
Gaines had a Mossberg 12-gauge shotgun, which she pointed at police, Johnson said. Records show she bought the gun last year.
The officers called for a tactical team and waited.
Not long into the standoff, Courtney left the apartment with a 1-year-old child and was arrested.
That left Gaines and the 5-year-old in the home.
"Gaines was posting video of the operation as it unfolded," Johnson said.
Gaines vacillated between agitated and calm during the encounter, he said. Several times she pointed the shotgun at officers.
At around 4 p.m., after hours of standoff, the woman threatened officers verbally and with the weapon, according to the police account.
"If you don't leave, I'm going to kill you. I'm going to kill you," Johnson quoted Gaines as saying.
One police officer fired a shot and Gaines fired back with double-aught buckshot. Officers responded with three shots and the woman was struck.
Police didn't say why the first officer fired.
The 5-year-old boy was hit in the arm during the crossfire.
It isn't clear if the boy was hit by a bullet or shrapnel, or who fired the shot that hit him, Johnson said. The boy's location during the gunfire is also unclear, he said.
Social media deactivated
Gaines' Facebook account was deactivated, but nothing was deleted, said Baltimore County department spokeswoman Elise Armacost, emphasizing that police wouldn't want video deleted because it could serve as evidence.
Authorities are working to obtain warrants for records of social media accounts belonging to Gaines, who "clearly had anti-government views," Armacost said.
As for whether police secured their own footage of the standoff, Johnson said no officer involved in the direct conflict was wearing a body camera. Asked later if police contemplated bringing body cameras to the scene during the hours-long standoff, Armacost said she would have to check and get back to reporters.
The officers will be placed on administrative leave, which is standard procedure in officer-involved shootings, according to police. Their names will be released around Thursday morning, as dictated by the Baltimore County Police Department's contract with its union, the department said.
Wanted on misdemeanors
A search of Maryland court filings shows that police filed traffic and criminal charges separately against Gaines in relation to a March 11 traffic stop. An officer issued Gaines citations related to her vehicle registration, insurance and tags -- offenses that would have commanded at least $560 in fines -- and filed criminal charges stemming from the same traffic stop the next day, according to court records.
She was originally pulled over for driving without a license plate. In place of a tag, she had a cardboard sign with a handwritten message warning government officials not to compromise her right to travel, he said.
Gaines was accused of disorderly conduct, resisting arrest, littering and failing to obey a reasonable and lawful order, all misdemeanors. A failure-to-appear warrant was filed when she did not show up to court July 13, court records show.
Police: Gaines filed assault charge
Courtney, the man in the apartment with Gaines, was wanted on an assault warrant filed by Gaines following a domestic violence incident in "the weeks prior" to Monday's standoff, Johnson said. Details were not immediately available, but Maryland court records show that Courtney was arrested for second-degree assault on June 28 and his case remains active.
The chief said it was unclear why he only took one child when he came out of the apartment Monday.
It was not clear if he was running or walking when he left, Armacost said. He was released from custody Monday, she said.
Police have yet to confirm the relationship of the two children to either suspect.
'Feisty' but 'respectful'
Anger against police violence remains high in the Baltimore area, which is still reeling from the death of Freddie Gray, the 25-year-old Baltimore resident who died on April 19
, 2015, after suffering a spinal injury while in police custody.
Gaines' uncle Jerome Barnett, 44, told the Baltimore Sun
that his niece "was feisty, but she was smart and she was respectful."
"My niece is a good person; I never knew her to be a rowdy person," Barnett told the paper.
CNN affiliate WBAL-TV reports
the case is the county's third officer-involved shooting of 2016 and the first fatal officer-involved shooting.
Following the death of another African-American at the hands of police, anger spilled out on social media pages.
Under scrutiny were authorities' initial uncertainty over whether officers wore body cameras, why certain videos had disappeared from Gaines' social media accounts and why three officers had arrived at her home to arrest her for misdemeanors and traffic violations.
Many users pointed out instances in which white people, such as Aurora, Colorado, movie theater shooter James Holmes, survived police encounters despite being heavily armed.
As details continued to emerge Tuesday, the outrage towards police was accompanied by a slew of tweets questioning the indignation. How, many people asked, can people rush to defend a woman who endangered her child by threatening police with a weapon when a child was in the home?