Scotty Joseph Lee, 32, was charged Tuesday with first-degree murder, two counts of armed criminal action and one count of first-degree assault in connection with the shooting.
Lee is accused of opening fire at Ballpark Village. One man, 38-year-old Corey Hall, of Spanish Lake, was killed when he was shot in the head. Another man, who was shot in the pelvic area, was in stable condition as of Monday.
A warrant was issued for his arrest Tuesday afternoon, and police said he was not yet in custody. Police asked for help finding him at a press conference Tuesday.
Police do not think the shooting was a random act, Major Mary Warnecke with St. Louis Metropolitan Police said at a press conference.
Several hundred people were at a ticketed event on the rooftop of the Budweiser Brew House just before 10 p.m. Sunday, police said. An argument broke out, and Lee allegedly pulled out a gun and fired. The two men struck were innocent bystanders.
"We don't believe (baseball fans) should have any cause for alarm when attending a ballgame in our city," Warnecke said.
Cardinals President Bill DeWitt III said there have been discussions about adding metal detectors to Ballpark Village, as well as other safety enhancements.
The Cardinals issued the following statement just after midnight Sunday:
"We are shocked and saddened by the senseless shooting at a private event at Ballpark Village Sunday night. There is nothing more important to us than the safety of our guests. We are praying for the victims and their families and we are working in every way possible to help the St. Louis Metropolitan Police Department with their investigation, including their effort to apprehend the individual responsible. We are grateful that our security staff and the St. Louis Police Officers on site were able to respond quickly to help care for the victims. We are urging anyone with information about what took place to contact the St. Louis Police Department or Crime Stoppers."