Sawyer Robison is charged with second-degree murder in the killing of Bradford Clarke.
Clarke was found dead in his home near Killam, southeast of Edmonton, where the two officers were shot.
Police searched for Robison after he was spotted leaving the scene.
He was arrested peacefully three days later on a rural road after a public plea from his parents to turn himself in.
Robison had been granted bail in June on the attempted murder charges but was rearrested after the murder charge was laid.
The two injured Mounties returned to work at the Killam detachment in the summer.
Constables Sheldon Shah and Sid Gaudette were wounded Feb. 7 when they went to search the Robison family farm.
Police said at the time that Robison was inside the house during the shooting, then drove off in a pickup truck. Clarke was found dead inside the home following a lengthy standoff.
Area residents have described him as a quiet photographer and musician who lived with his uncle. His parents lived in another home on the same property.