A man has been charged with murder over the killing of eight people at massage parlours in Atlanta, Georgia.
The suspect, named as Robert Aaron Long, faces multiple counts of murder as well as aggravated assault.
Tuesday's shootings took place at two spas in Atlanta and another in Acworth, about 10 miles west of Woodstock - which left eight people, at least four of them Asian women, dead.
The four killed in the shooting near Woodstock were Delaina Ashley Yaun, 33, of Acworth; Paul Andre Michels, 54, of Atlanta; Xiaojie Tan, 49, of Kennesaw; and Daoyou Feng, 44.
The injured survivor was Elcias R. Hernandez-Ortiz, 30, of Acworth, authorities said.
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 rise in crimes against Asian-Americans.
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.
According to two law enforcement sources involved in the investigation, Long attempted to justify his actions when he told police he thought about killing himself, but decided instead to "help" others with sexual addictions by targeting spas.
Investigators believe that when he was captured, Long might have been en route to Florida to to commit a further crime.
Long had a 9 mm firearm in his car when he was arrested, according to reports.
He purchased his gun legally at a local gun store, Big Woods Goods in Holly Springs, Georgia, an attorney for the company confirmed.
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.
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".
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.
Atlanta police said they were increasing patrols around businesses similar to those attacked.