Omaha Police say four people in a white, four door sedan pulled into the drive through at the "Scooter's" at 158th and West Maple Road around 9:15 Tuesday night demanding free drinks.
A front seat passenger brandished a knife when told no, and they drove away without paying for three coffees.
Investigators say the driver was described as a white female teen with braided hair.
The armed passenger was described as a black male in his teens with dreadlocks.
Anyone with information is asked to contact "Omaha Crimestoppers" at 402-444-STOP, at www.omahacrimestoppers.org or on the P3 Tips mobile app: www.p3tips.com