Synthetic cannabinoids are currently the largest group of new psychoactive substances. Among them, one of the most recent compound in Vietnam is AMB-Fubinaca. No quantitative method has been officially implied for AMB-Fubinaca in criminal evidences, thus, making the police investigations burdensome. This study, for the first time, aimed to develop and validate the gas chromatography with flame ionization detector (GC-FID) method to determine and quantify AMB-Fubinaca in criminal evidences found in the South of Vietnam from 2016 to 2018. Chromatography separation was achieved on diphenyl dimethyl polysiloxane GC column (30 m × 0.32 mm × 0.25 µm) with a total run time of 10 minutes. The method was validated in terms of specificity, linearity, precision, accuracy, and sensitivity. The method satisfied all validation requirements. The limit of detection (LOD) and quantitation (LOQ) for AMB-Fubinaca was 1.5 μg/mL and 4.5 μg/mL, respectively. Tested with 30 criminal samples collected in Vietnam from 2016 to 2018, the validated method proved its cost-effectiveness, simplicity, and usefulness for the rapid determinations of AMB-Fubinaca, as compared to the GC-MS method. In conclusion, the GC-FID could be a potential analytical method for the rapid and inexpensive determination of AMB-Fubinaca in criminal evidences.