The Grant County K-9 dog Diego had a busy night Friday, helping make three arrests in traffic stops.

Two people were arrested on marijuana charges after a traffic stop in Platteville Friday night.

Platteville police stopped a car with loud exhaust traveling the wrong way on a one-way street at Main Street and Oak Street around 9:05 p.m.

Police requested the K-9 unit to go to the scene. K-9 Diego alerted to the odor of a narcotic on a vehicle, according to the sheriff’s department.

Jacob E. Piper, 18, Roscoe, Ill., was arrested for possession of marijuana. A 17-year-old Roscoe, Ill., male was arrested on charges of possession of marijuana and possession of drug paraphernalia.

Diego was on the scene for another arrest about three hours later, on U.S. 151 at Little Platte Lane in the Town of Platteville Saturday around 12:10 a.m.

After Diego alerted to the odor of a narcotic, Jerome Odell Dyson Jr., 24, Dubuque, was arrested for operating a motor vehicle with a detectable amount of a restricted substance and possession of marijuana, along with a valid warrant. His passenger, Tony Jamar Criss, 27, Dubuque, was also arrested for possession of marijuana.

Less than three hours later, Diego was requested again for a traffic stop on U.S. 18 near Fennimore around 2:55 a.m.

After Diego alerted to the odor of a narcotic, Jonatan A. Rodriguez, 20, Cassville, was arrested for possession of drug paraphernalia and operating a motor vehicle with a detectable amount of a controlled substance.