Data contain repeated values of variable suspect.  Each suspect is viewed by multiple witnesses and each witness (1) declines to identify a suspect, (2) chooses a foil, or (3) chooses the suspect.
Source: Fictional data inspired by Wright, D. B., and A. T. Sparks. 1994. Using multilevel multinomial regression to analyse line-up data. Multilevel Modelling Newsletter 6: 8-10.