A 26-year-old man was sentenced Thursday to more than 27 years in prison for fatally choking his mother's Twin Cities boyfriend, someone the son viewed as a rival for the woman's attention.

Shawn R. Doherty, 26, pleaded guilty last month to second-degree murder in the death in January 2014 of Paul Bulen, 55, of Mahtomedi, at the home of the defendant's mother.

"There is no consequence for the defendant that can make up for the loss of Paul Bulen's life," said Assistant St. Louis County Attorney Michelle Anderson "The victims can't get back what was lost. I am deeply saddened for the suffering the defendant has caused Paul Bulen's friends and family, and I expressed my support to them."

Bulen was found unconscious outside the mother's Babbitt home dressed only in underwear and a T-shirt.

The defendant's mother, 52-year-old Lynda Doherty, was running errands at the time of the attack. Before she left, Bulen asked her to lock the bedroom door because he was afraid of her son, according to the criminal complaint.

She also told officers that the night before Bulen died her son had repeatedly entered her bedroom and woke her up, and at one point told her he thought Bulen was coming between them and that he planned to kill him, the complaint added.

Officers found the bedroom door forced open. In the bathroom they found Shawn Doherty in a fetal position in the bath tub, the complaint read.

With credit for time served since his arrest, Shawn Doherty should be eligible to leave prison on supervised release within about 17 years.