GRAND RAPIDS, Mich. (WOOD) — Attorneys representing a former Michigan State Police detective sergeant charged with murder after he hit a man with his cruiser, killing him, have asked a federal judge to throw out the case.

A pretrial motion was filed Tuesday to dismiss second-degree murder and involuntary manslaughter charges against Brian Keely in the death of Samuel Sterling. The motion asks for immunity from criminal prosecution, citing the U.S. Constitution’s Supremacy Clause.

In order to be granted immunity under the Supremacy Clause, it must be proven that Keely was authorized to perform the act by U.S. law and did not do more than what was necessary and proper to carry it out. The motion filed Tuesday argues both of those tenets are true in Keely’s case.

Looking to arrest Sterling, 25, of Grand Rapids, on a number of warrants, authorities tracked him to a Kentwood gas station on April 17. Police say he ran away when they moved in to get him. Officers chased him on foot to a nearby Burger King while Keely pursued in an unmarked cruiser. Video released by MSP shows Sterling being hit by Keely’s SUV near the restaurant’s entrance. Sterling was hospitalized and died hours later.

A declaration from Supervisory Deputy US Marshall Matthew Ortiz included in the defense’s motion states Keely was working for the U.S. Marshals Service at the time of Sterling’s death.

“The fugitive investigation that led to an effort to apprehend (Sterling) on April 17, 2024 in Kent County, Michigan was an authorized federal operation of the United States Marshals Service as part of the Grand Rapids Fugitive Task Force,” Ortiz wrote, saying Keely was included on that task force.

The memorandum filed with the motion claims Keely did not “do more than what was necessary and proper to fulfill his sworn federal duties.” It claims he did not intend to hit Sterling and was instead trying to stop him from entering the Burger King.

“Keely drove at an angle which he believed would safely cut off Sterling from the door, prevent him from entering the restaurant, and cause Sterling to change direction away from the Burger King lobby if he chose to continue his unlawful escape efforts,” the memorandum claims.

Previously, lawyers had argued whether the murder case should be tried in state or federal court. In late August, U.S. District Court Judge Hala Jarbou decided that the case against Keely would be moved to federal court because he was acting as part of a federal task force when he hit Sterling. A trial has been scheduled to start April 21 in a federal courtroom in Lansing.

However, the Michigan Attorney General’s Office asked for the case to be sent back to state court. Earlier this month, the AG filed a motion seeking a hearing on the matter, saying it is still investigating, but that “it is clear to the State of Michigan that Keely’s employment status at the relevant points in time is debatable.”