A man has been charged with murder over the killing of eight people at massage parlours in Atlanta, Georgia.
Officials cannot yet confirm if the attack, in which six Asian women were killed, was racially motivated. Four victims were named on Wednesday.
The suspect, named as Robert Aaron Long, faces multiple counts of murder as well as aggravated assault.
Cherokee County Sheriff Frank Reynolds said the suspect may have been a patron and claimed to have a "sex addiction".
The attack comes amid a sharp uptick in crimes against Asian-Americans.
Four of the victims have been identified by Cherokee County officials as Ashley Yaun, 33; Paul Andre Michels, 54; Xiaojie Tan, 49; and Daoyou Feng, 44. Elcias R Hernandez-Ortiz was identified as having been injured.
What did police say?
In a news conference on Wednesday, investigators said Mr Long, 21, of Woodstock, Georgia, admitted to the shooting spree, and said that he denied that the attack was motivated by race.
He has been charged with four counts of murder and one count of aggravated assault, according to the Cherokee County Sheriff's Department.
"He apparently has an issue, what he considers a sex addiction, and sees these locations as a temptation for him that he wanted to eliminate," said Capt Jay Baker, adding that Mr Long was caught with a 9mm handgun and did not resist arrest.
But Capt Baker's remarks - that "yesterday was a really bad day for him and this is what he did" - came in for widespread criticism for appearing to sympathise with the alleged perpetrator.
Massage parlours are known to sometimes provide prostitution services, but authorities say there is no indication yet that this is the case at the targeted locations.
"These are legally operating businesses that have not been on our radar," said Atlanta Mayor Keisha Lance Bottoms, who added that the city would not engage in "victim shaming, victim blaming".
Police also noted it is still too early in the investigation to definitively state a motive and that the suspect appeared to have been acting alone.
Ms Bottoms said that he was on his way to Florida, possibly to commit more shootings, when he was arrested.
The suspect's parents helped to identify him, officials told reporters.
According to CBS News, the suspect told investigators that "he loved God and guns".
What do we know about the shootings?
The first happened at about 17:00 (21:00 GMT) on Tuesday at Young's Asian Massage in Acworth, Cherokee County.
Two people died at the scene and three were taken to hospital, where two more died, sheriff's office spokesman Capt Baker said. He later confirmed the victims were two Asian women, a white woman and a white man, and said a Hispanic man had been wounded.
Less than an hour later, police were called to a "robbery in progress" at Gold Spa in north-east Atlanta. In the recording of the 911 call released on Wednesday, a woman tells the dispatcher that she's hiding from the assailant.
"Do you have a description of the male?" the operator asks.
"We're hiding right now," the woman replies. "They have a gun."
"Please come, ok?" she says.
When authorities arrived at the spa, "officers located three females deceased inside the location from apparent gunshot wounds", police said.
While there, officers were called to a spa across the street, called Aromatherapy Spa, where they found another woman shot dead.
On a second 911 call, a woman tells the operator that she got a call from a friend who said a man had entered the spa and fired a gun.
"They said some guy came in... We heard a gunshot and the lady's passed out in front of the door," she says. "And everybody is scared and everybody is hiding."
Investigators who had studied CCTV footage then released images of a suspect near one of the spas. Police said that, after a manhunt, Robert Aaron Long was arrested in Crisp County, about 150 miles (240km) south of Atlanta.
Authorities in South Korea said they were working to confirm the nationalities of the four women of Korean descent.
Who are the victims?
Police have only identified the people who were attacked in Cherokee County at this time.
Details have been slow to emerge. Here is what we know about the named victims so far.
Ashley Yaun and her husband had gone to Young's Asian Massage for a couples massage, according to an online fundraiser.
Her husband survived the attack and was unharmed. The couple have two children.
"We just don't know how to do any of this alone," the GoFundMe page says.
A GoFundMe for Mr Hernandez-Ortiz, the only victim to survive the attacks, says that he is intensive care after being shot in the forehead, lungs and stomach.
His daughter Yoseline, 9, told WGCL-TV that "he is a really good dad," and "I don't want him to go."
Anger and fear in Asian communities
By Zhaoyin Feng, BBC Washington
Heartbroken, fearful, angry, fed up. These are some shared feelings of people who showed up at a vigil in Washington DC the night after the shooting.
Around 100 people marched in Chinatown and lit candles, mourning the eight lives lost in Atlanta - six of them of Asian descent.
The authorities have not linked the killing with anti-Asian hate crime. But many here believe the shooting is yet another senseless attack against Asians and Asian-Americans during the pandemic.
"It's scary to be an Asian-American woman anywhere in the US," an Asian woman told me. She said it was finally time for her to speak up, after being told by her parents to stay silent about racism she experienced while growing up.
There's a myth about Asian-Americans being the quiet "model minority". But those who attended the vigil, both Asians and non-Asians, spoke loud and clear with a unified voice.
"We will not fight racism with racism," a Korean-American man spoke to the crowd emotionally, "We will fight racism with unity!"
What has the reaction been?
Though authorities say it is too early to know if the victims were targeted because of their race, many online have criticised a recent rise in anti-Asian hate crimes, which activists have linked to rhetoric blaming Asian people for the coronavirus pandemic.
The advocacy group Stop AAPI Hate, which tracks attacks on Asian Americans and Pacific Islanders acknowledged a motive was unclear, but said "right now there is a great deal of fear and pain in the Asian American community that must be addressed".
It called the shootings "an unspeakable tragedy" for both the victims' families and the Asian-American community, which has "been reeling from high levels of racist attacks".
"A motive is still not clear, but a crime against any community is a crime against us all," Mayor Bottoms said in a statement, adding that she had been in communication with the White House.
Mr Biden tweeted that he and the first lady were "keeping everyone impacted by the shootings in Atlanta in our prayers".
"We don't yet know the motive, but what we do know is that the Asian-American community is feeling enormous pain tonight. The recent attacks against the community are un-American. They must stop," he said.
Vice-President Kamala Harris, the first Asian-American to hold the office, said during a Wednesday meeting with Irish officials: "I do want to say to our Asian-American community that we stand with you and understand how this has frightened and shocked and outraged all people."
Ben Crump, a leading civil rights lawyer, also took to Twitter, saying: "Today's tragic killings in #Atlanta reaffirm the need for us to step up and protect ALL of America's marginalised minorities from racism."
Atlanta police said they were increasing patrols around businesses similar to those attacked.
Georgia Governor Brian Kemp praised law enforcement officials for their response to the shootings, and said: "Our entire family is praying for the victims of these horrific acts of violence."