Jinagh Navas-Rivas pleaded guilty in December to trafficking cocaine and unlawfully transferring a .22-calibre Ruger pistol with ammunition.
In addition to the four-year jail term, Navas-Rivas has been banned from possessing weapons for life.
Navas-Rivas lived as a foster son with Robertson, his wife and their other children between 2007 and 2009, and when police issued an arrest warrant for him in late 2011, Robertson made a public plea urging him to surrender.
Robertson says Navas-Rivas has taken responsibility for his actions and he wishes him the best.
Robertson adds it's been a tough time for Navas-Rivas and the families who have been part of his life. (CKNW)
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