A large number of people witnessed the shooting before the unknown killer left the popular Nivå nightclub on Kungsportsavenyn in the city centre.
”We know the identity of the deceased man; he is known to the police,” superintendent Peter Kron told local newspaper Göteborgs-Posten.
“But since we haven’t yet been in contact with his parents I don’t want to say anything else about him.”
Michelle Waffenius, 19, was standing nearby with a group of friends when the shooting took place.
”We didn’t understand what had happened. We just saw this guy fall to the ground,” she told local news website GT.se.
“I reckon we were about three metres away. I was looking on right when it happened but I didn’t understand what was going on.”
Security guards blocked all exits in a bid to detain the shooter as soon as they realised what had happened. Guests at the nightclub were let out one at a time and were each asked to identify themselves and provide a short statement.
“All we’re prepared to say for now is that there’s an ongoing forensic examination and we’re planning to question witnesses over the course of the day,” said police spokeswoman Pia Goksöyr.