When a busload of troopers stops a DUI driver, how do they decide which one has to make the arrest?

DUI / Possession of Marijuana:

SUNDERLAND, MD. — According to the Maryland State Police, on 6/27/15 at 9:11 am, Trooper Rucker responded to a reported hit and run accident at the split on Rt. 2 and Rt. 4.

Police say that both vehicles were located by an Off Duty Trooper at Rt. 4 and Kyler Rd. in Huntingtown.

The driver, Kelsey L. Hardister, 25, of Clayton, NC, was arrested for DUI.  A search revealed she had a knife concealed on her person and a counterfeit $100 bill.  She was incarcerated at the Calvert County Detention Center.  The passenger, Adolph J. Scott, 30 of Henderson, NC, was found to be in possession of less than 10 grams of Marijuana and was issued a Civil Citation and was released.

Ownership of the Jaguar they were driving was unable to be established at that time and it was placed in storage.  The owner was later identified and was notified of the vehicle storage.