He suffered three severe wounds during combat and was assigned to detached duty in Washington, D.C., joining General Lafayette Baker's intelligence service as a detective.
Following the assassination of President Lincoln on April 14, 1865, Conger was ordered to accompany a detachment of 25 Union soldiers from the 16th New York Cavalry Regiment, led by Lieutenant Edward P. Doherty.
The soldiers pursued Booth through Southern Maryland and across the Potomac and Rappahannock rivers to Richard Garrett's farm, just south of Port Royal, Caroline County, Virginia.
Booth and his accomplice, David E. Herold, had been led to the farm by William Storke "Willie" Jett, formerly a private in the 9th Virginia Cavalry, whom they had met before crossing the Rappahannock.
[3] Conger set fire to the barn and Sergeant Boston Corbett mortally wounded Booth by shooting him in the neck.