Officers of the Traffic Police in Veliko Tarnovo, the road-police unit for the regional city, identified a driver as a person who had used narcotic substances.[1] On 3 November in Veliko Tarnovo, the regional city, officers carried out a roadside check of a passenger car that at the time was being driven by a 30-year-old man described as having Ukrainian citizenship.[1][2][3][4] As part of that roadside check, officers administered a test to the driver for the use of narcotic substances using a technical testing device.[1][4] The device returned a positive reaction for cannabis as well as a positive reaction for cocaine in the same roadside test.[1][2][5][3][4]

After receiving the roadside result, the driver refused to provide a blood sample for further confirmatory testing.[1][2][5][3][4] Following the refusal, officers detained the driver for a period of up to 24 hours under the Interior Ministry Act.[1][6][4] After the detention, police opened fast-track proceedings against the driver in connection with the drug-driving case.[1][2][5][3][4]