Tulsa police say officers from the Riverside Division were flagged down by a motorist shortly before 1:30 Friday morning at 41st and Sheridan.
The person told cops he just saw someone in a blue, Ford Contour, pointing a gun at another person in the car.
Officers spotted the car a short time later and pulled them over.
Three of the four people were ex-cons.
Inside the car was 43-year-old Bennie Johnson, Jr., 33-year-old Roosevelt Tolon, 25-year-old Korrine Vann and 45-year old Shelly Leonard.
Cops also found a semi-automatic gun.
Tolon was arrested for Possession of Firearm.
Vann was arrested for Driving Under the Influence, Resisting Arrest and eleven other charges.
Leonard was arrested on a warrant for Driving Under a Suspension.