An English astrophysicist was killed by a stray bullet that travelled through a wall and hit him in his bed, US authorities have said.
Dr Matthew Willson, 31, from Chertsey, Surrey, was found with a single gunshot wound to the head.
Police were called to an apartment in Brookhaven, Atlanta, at 02:00 local time (07:00 GMT) last Sunday.
Sgt Jake Kissel, from the Brookhaven Police Department, said the shooting was believed to have been a random act.
There have been no arrests so far.
Sgt Kissel said the stray bullet that hit Dr Willson travelled less than 100 yards (91m) and entered through an exterior wall of the apartment.
“The two apartment complexes where the gunfire took place and where Matthew was staying, they’re separated by a patch of woods, so they back up to each other,” he said.
“We’re saying it’s the reckless discharge of firearms from one apartment complex and the stray bullet travelled through the woods and entered his apartment.”
Dr Willson was in the US visiting his girlfriend Katherine Shepard.
Aman Kar, who shared the flat with Ms Shepard, told BBC Breakfast “multiple rounds of gunshots” were fired in the opposite complex “about 20ft away” in the early hours of Sunday 16 January.
Mr Kar added that the gunfire “had happened before… but not for so long”.
He said the pair moved into the apartment last August and recalled two similar incidents in October and November when police had been called – but said it was “just a few shots” on those occasions.
“This time it kept going on for 20 or 30 minutes, until one of the stray bullets hit Matthew.”
Mr Kar said he hoped somebody would come forward with more information on the incident “because as much as it’s an accident, it’s also not, because the sheer number of shots that were fired.
“It’s hard to see how something so random happened. It’s reckless… reckless people with guns.”
Sgt Kissel said investigators were following up on all leads, adding: “We’re receiving tips from the public and our investigator team has been working around the clock to ensure that we’re tracking down the individuals that are responsible.”
He said an innocent bystander being struck by a stray bullet was the first incident “of its kind” in Brookhaven and was an “alarming” and “tragic event”.
“Even though we believe that it was a random act and complete reckless discharging of firearms, we’re still approaching it as a homicide,” he added.
Dr Willson was taken to a local trauma centre but died of his injuries.
The Foreign Office said it was “supporting the family of a British man following his death”.