Atlanta massage parlour killings: US cop posted racist T-shirt before saying suspect Robert Aaron Long was having 'bad day'

The suspect in a spate of shootings at Georgia massage parlours that left eight people dead was having a "really bad day" before the murders, according to police - a comment that sparked outrage on social media.

Robert Aaron Long, 21, admitted to opening fire at three massage parlours in the Atlanta area.

The 21-year-old allegedly killed four people at Young's Asian Massage Parlor in the city of Acworth just outside of Atlanta shortly before 5pm on Tuesday (local time). 

Less than an hour after the first incident, police were called to a robbery at Gold Spa (roughly 40km from the first shooting) and found three people dead with gunshot wounds.

While police were at the scene, another person was killed at the Aromatherapy Spa massage parlour across the street from Gold Spa.

"He was kind of at the end of his rope," Cherokee County Sheriff's Captain Jay Baker said during a press conference.

"Yesterday was a really bad day for him and this is what he did."

The spate of shooting left eight dead - six of whom were Asian women.

Baker said the 21-year-old admitted to the shootings, but denied they were racially motivated.

"The suspect did take responsibility for the shootings… He does claim that it was not racially motivated."

Captain Baker has come under fire for sharing a photo of a t-shirt based off the Corona beer labelled, "COVID-19 imported virus from CHY-NA".

"Love my shirt! Get yours while they last," he wrote on a Facebook post, which has since been deleted.

Cherokee Sheriff spokesperson Frank Reynolds told reporters on Wednesday the man may have been a regular customer at these massage parlours.

"He made indications that he has some issues - potentially sexual addictions," he said.

"We believed that he frequented these places in the past and may have been lashing out."

But social media users were enraged over the officers' choice of words, and said "having a bad day" isn't an excuse for murdering eight people.

"I've had bad days… I never went on a murder spree… what an odd choice of words," one Twitter user commented.

"You know who it was a really, really bad day for? The eight people and their families who this man killed," another said.

"I had a bad day myself yesterday and everyone I came in contact with is still alive."