Police are investigating after three men were injured in separate shootings in St. Paul this weekend.

On Sunday night, a 22-year-old man was wounded in the area of the Dunning Recreation Center on Marshall Avenue, near Lexington Parkway.

Early Sunday, a 38-year-old man was shot in the head, though he’s already been treated and released from the hospital. The man was wearing a flat-brimmed baseball hat and the bullet lodged in the hat’s forehead area, according to police.

And an argument in an apartment building on Saturday afternoon ended with a 48-year-old shooting a 59-year-old man in the leg, according to a criminal complaint filed against Sean Arnell Allen on Monday.

An officer used a tourniquet on the man’s leg and he was taken to the hospital in critical condition, the complaint said. Police were called to the shooting on Asbury Street, about a block east of Snelling Avenue, on Saturday at 1:30 p.m.

Police chased Allen for several blocks and saw him crouching by a vehicle. A gun was found within 5 feet of Allen and the snow around it “had melted from the warmth of the recently fired gun,” according to the complaint charging Allen with second-degree assault.

Allen told an investigator he shot at the man, but said he did not try to hit him and “could not explain why he became mad enough to shoot someone,” the complain said.

Allen was convicted in 1989 of aiding and abetting a homicide and spent seven years in prison in Wisconsin, the complaint said. Soon after his release, he was convicted of possession of a firearm by a prohibited person, also in Wisconsin.

Police have not made arrests in Sunday’s shootings.

Officers were called to the area of the rec center at 10:20 p.m. on a report of a man being shot. Soon after, someone dropped off the 22-year-old at Regions Hospital and he was immediately taken in for treatment, according to a police report.

Information about the man’s condition was not available Monday, said Steve Linders, a St. Paul police spokesman.

On Sunday at about 1:15 a.m., police responded to a shooting on Arkwright Street, not far from Cayuga Street.

A witness reported the 38-year-old man was sitting in a vehicle when a male emerged from behind a shed and fired several shots at the vehicle before running away, Linders said.