Police are appealing for information following an incident in the car park of the Brentwood Centre in Doddinghurst Road, Brentwood just before midnight on Saturday, February 18.
Officers attended and found a man with a gunshot wound to his shoulder.
The man was taken to hospital and his injuries are not thought to be life-threatening.
Investigations are ongoing.
Detective Superintendent Stuart Hooper, of the Essex and Kent Serious Crime Directorate, said: “We would like to speak to anyone who was at or near the Brentwood Centre between 7pm yesterday and 1am today.
“The venue was very busy during this time due to a sporting event taking place there and someone will have seen something that will help this investigation.
“We are particularly keen to speak to anyone who attended the venue and has dashcam video footage in their car.
“I believe this was an isolated incident and don’t believe there is any risk to the wider public.
“I would urge members of public to go about the daily business as usual.”
Anyone with any information about the incident is asked to contact the Essex and Kent Serious Crime Directorate on 101 quoting incident 50 of 19/02 or Crimestoppers anonymously on 0800 555 111.