ST. PAUL — Three people were killed and a fourth person was critically wounded in a shooting at an apartment building in St. Paul early Friday, and police said one suspect was later found dead.

Officers were called to the building around 1 a.m. Police using dogs found a 18-month-old girl who had been taken from the building and one suspect hiding in a nearby shed about two hours later, just as authorities were getting ready to issue an Amber Alert. She was taken to a hospital for evaluation but was not injured. That suspect was booked into the Ramsey County Jail.

The second suspect was found dead later in the morning by officers canvassing the area. The cause of that suspect’s death was not immediately released.

“Investigators are still working to determine exactly what led to the shootings,” police said in a statement. “It is believed that one of the suspects was the shooter.”

Police also said investigators were trying to determine the relationship between the suspects and victims, but it’s believed they knew each other.

Names of the victims and the condition of the injured person were not immediately released. Autopsies were planned.

Police spokesman Steve Linders said investigators had a lot of work ahead of them because they were dealing with three crime scenes spread over a large area.