Portland, Tenn., Police Chief Richard Smith identified the suspect taken into custody as Marquinta Jacobs, 36, of the 3rd Brigade Combat Team, 1st Infantry Division, The (Nashville) Tennessean reported.
Smith said officers first looked for Jacobs at his mother's house in Portland where they found his motorcycle and learned he had left in his mother's car. Police later pulled him over and arrested him without incident and booked him into the Sumner County Jail, the newspaper said.
Smith said Jacobs was armed with two semiautomatic pistols when arrested.
Jacobs is suspected in the death of a civilian who worked for the U.S. Army Human Resources Command who was shot about 5:40 p.m. local time Wednesday outside the U.S. Army Human Resources Command headquarters at Fort Knox. The man, identified only by the initials L.G., was pronounced dead at Ireland Army Community Hospital, WDRB-TV, Louisville, reported.
Chris Grey of the independent Army investigative agency said in a news release that investigators had determined it was "a personal incident and not a random act of violence."