A hail of gun violence in St. Paul began with a teen shot to death in a park Sunday evening and ended almost exactly 24 hours later when a 30-year-old man was fatally shot at an apartment in the city's Payne-Phalen neighborhood.

Those 24 hours also saw six injured in shootings in the city. Since Friday, police logged more than 30 reports of shots fired.

In the most recent incident, at 6:45 p.m. Monday, police went to an apartment building in the 400 block of E. Magnolia Avenue, where they found a 30-year-old man with a gunshot wound. He was taken to Regions Hospital, where he died.

Police were seeking at least one suspect, according to scanner audio. Police also said a white Mercedes sedan "is involved," and at least one officer on scanner traffic reported that the Mercedes was seen "earlier" at Indian Mounds Park, where multiple shots broke out during a large gathering Sunday night, killing an 18-year-old man and injuring another person.

It was not clear whether the shootings Sunday night and Monday night were related. "We're still trying to figure that our ourselves," St. Paul police Sgt. Mike Ernster said late Monday. "We're dealing with people who think it's OK to resort to violence … with firearms to settle their differences, and we're not going to stand for it."

Ernster called the level of violence "outrageous." He said residents will notice a "more robust police presence in areas of the city where shootings most frequently occur."

A "shooting response team" will be created to respond to shots-fired calls and "the response will be immediate and the information gathered will be used to identify and arrest suspects and prevent further violence," Ernster said.

Police arrested a 24-year-old man Monday morning in connection with the Sunday shooting and booked him on suspicion of murder.

On Monday about 1:30 p.m., police found two shooting victims at St. Albans Street and W. Central Avenue. They were taken to Regions Hospital and treated for noncritical injuries, police spokesman Steve Linders said.

On Sunday, police confirmed that one man had been fatally shot and later said there was a second victim in connection with the melee that broke out around 7:30 p.m. during a barbecue attended by about 300 people at the park, near Earl Street and Mounds Boulevard.

The man who was fatally shot was identified in various Facebook posts as Bobby Collins. He was pronounced dead at the scene. The second victim was treated at a hospital and released, said Ernster.

Linders said that there is no indication that the shooting is related to the many shots-fired calls that police received between late Friday and early Monday morning. In one of those incidents, a man was shot in the chin. On Sunday night, a man entered the CVS pharmacy at Snelling and University avenues with a gunshot wound to his arm.

The 24-year-old arrested in connection with Sunday's shooting has a history that includes convictions for theft, marijuana possession and disorderly conduct. He had not been charged as of Monday evening. The suspect was arrested without incident at St. Paul police headquarters, Linders said, and there may be other suspects.

The Ramsey County medical examiner is working to identify the victim.

Staff writer Pat Pheifer contributed to this report. Karen Zamora • 612-673-4647 Chao Xiong • 612-270-4708