DETROIT—A Canadian man has been sentenced to 15 months in a U.S. prison nearly 20 years after he smuggled immigrants across the Detroit River.

Justice moved slowly in the case of Thanh Nguyen because he fled home to Ontario, Canada, and didn’t appear for his sentence in 2000.

Nguyen, now 42 years old, was arrested last summer in Windsor, Ontario, a city across the river from Detroit. He was sentenced Thursday for smuggling immigrants on a boat back in 1999. Nguyen apologized to a judge, saying he was immature at the time.

It’s unclear why it took so long to find him. Defence attorney Marshall Goldberg says Nguyen wasn’t “living in the shadows.” He had a driver’s license and operated businesses in the Windsor area.