The others had “various injuries”, he added.
Police have not got anyone in custody over the shooting, Fitzman said, urging the public to provide any information that could help the investigation.
Several agencies are involved in the investigation, including the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Fire rescue services at on the scene Saturday night and had cordoned off the area.
This year, there have been at least 403 mass shootings -- defined as a shooting involving at least four victims, dead or wounded -- across the United States, according to the Gun Violence Archive.
At least 12,416 people have been killed in firearms violence this year in the United States, according to the GVA.
- AFP