A Virginia police officer who was suspended for violating department policy against conducting civil immigration enforcement for Immigration and Customs Enforcement will return to duty Friday.

Fairfax County Police Chief Edwin Roessler said in a Wednesday statement that the unnamed officer would be back on the force, although he noted that an internal investigation into the matter was still ongoing.

“We have one of the best police forces in the U.S. and I have confidence that our officer will represent us well throughout his career. Our internal administrative investigation continues as prescribed by policy,” Roessler said.

The suspension occurred after the officer in question responded to a traffic accident on Sept. 21. At the scene, the officer discovered that one of the drivers did not have a Virginia driver’s license and, after checking with the Department of Motor Vehicles, found that the individual had been given an administration violation for failing to appear at a deportation hearing.

The officer then called an ICE agent who was assigned to the warrant and held the person and turned them over to ICE. He was given an ankle monitor and released by ICE hours after the initial detention.

Under a policy that has been in place since 2007, the Fairfax County Police Department has not allowed officers to arrest individuals based on civil violations of immigration law, but if an immigrant is arrested for a crime, their immigration status is checked when they are booked at the county jail.

The chief said that the officer had only been with the department for a few years and had made a mistake.

“This is an unfortunate issue where the officer was confused,” Roessler said. “We have trained on this issue a lot. This is the first time we’ve had a lapse in judgment, and the officer is being punished.”