Boris Panovski has been arrested in connection with the shooting death of Caledon businessman Donato Frigo.
He was arrested on Sunday at Pearson Airport as he was reentering the country.
Frigo, 70, was a vice-president at Toronto-based Hady Construction Associates.
Frigo was riding a horse in the Hullett Provincial Wildlife Area on Sept. 13 when a man approached and shot him.
A woman who was riding with Frigo had minor injuries.
A Canada-wide warrant had been issued for Panovski’s arrest.
He is facing first-degree murder and attempted murder charges.