From the National Archives.
Report of the Select Committee on Assassinations of the U.S. House of Representatives
A. James Earl Ray Fired One Shot at Dr. Martin Luther King Jr., the Shot Killed Dr. King
"From a combination of field investigation, scientific data and admissions by Ray, the committee was convinced that Ray purchased the rifle, transported it to the scene of the crime and abandoned it near the scene immediately after the shooting.
First, the evidence is conclusive that Ray purchased a .30-06 caliber Remington Game-master slide action rifle, serial No. 461476, model 760, with a Redfield variable telescopic sight, serial No. A17350 and Weaver sight mount. This rifle, sight and mount were recovered by police officers immediately after the assassination and were later designated exhibit "Q2" by the FBI.
Ray repeatedly admitted, as he did under oath at a committee public hearing, that on March 29, 1968, he purchased a .243 caliber rifle and a telescopic sight at the Aeromarine Supply Co. in Birmingham. Further, Ray admitted that the next day he exchanged the .243 caliber rifle for a more powerful .30-06 Remington Game-master. That rifle was identified as the rifle found in front of Canipe's Amusement Co. on April 4, 1968.
Ray's admission about the purchase and exchange was corroborated by the statements of U.L. Baker and Donald Wood, the Aeromarine employees who dealt with Ray on March 29 and 30. Wood, in fact, identified Ray as the man known to him as Harvey Lowmeyer who, on March 30, received the .30-06 rifle in exchange for the original .243 purchase. In addition, the Aeromarine sales receipt reflects the initial purchase and subsequent exchange by Lowmeyer, the alias Ray admitted using at the time of the rifle purchase."