Police are still investigating Friday night’s shooting in the Scarborough Walmart parking lot.
Ryan Townsend, 24, was critically injured and taken to Maine Medical Center in Portland for emergency surgery.
Customers were kept inside the store, which went on lockdown as police responded.
No arrests have been made.
Police questioned 24-year-old Tyler Hish of Scarborough. He was released after speaking with investigators.
Police are still trying to contact witnesses, hoping they may assist in the investigation.