Authorities have detained the unidentified man, the 28-year-old, the 23-year-old, and a 25-year-old individual.
The adult male, and father of the deceased children, remains hospitalized but is no longer in intensive care.
The investigation remains ongoing, with authorities recovering two firearms at the scene.
Subsequently, a 27-year-old suspect was apprehended in connection with the shooting.
The incident has deeply affected the close-knit Elkhorn community, with neighbors expressing shock.
Individuals with any pertinent information are encouraged to contact Milwaukee Police at (414) 935-7360.
The investigation was focused on a vehicle in an alley with an Iowa license plate.
The individual fired their weapon, prompting officers to respond with gunfire, as stated by the DOJ.
There are no known threats to other areas of the city at this time.
One vehicle pull up to another and gunfire erupted.