A man was shot in the leg at a house in Dovecot on Sunday night.
The 28-year-old presented himself at Whiston Hospital with injuries consistent with gunshot wounds but was discharged before police had been informed.
Merseyside Police are treating the incident as a targeted attack although the man, whose injury is not thought to be serious, is refusing to co-operate.
Officers are currently in attendance at a property on Colwell Road and an investigation is underway.
Detectives are looking to trace a man dressed in a grey tracksuit and a woollen hat, who was seen in the area around the time of the incident.
He was later seen running along Snowberry Road.
Anyone withinformation about this incident is urged to contact the MSOC gun crime hotline on 0800 230 0600 or Crimestoppers anonymously on 0800 555 111.