A Sandy Springs man was sentenced to life plus 20 years in prison late Monday for his role in a violent Roswell home invasion, the Fulton County District Attorney's Office announced Tuesday.

Rueben Allen, 32, was the last of three defendants to be sentenced in the case. A jury found him guilty of armed robbery, aggravated assault, false imprisonment and battery. He is not eligible for parole.

Authorities said Allen and an accomplice, James Marino, ambushed and pistol-whipped a pawn shop owner outside his home on Horseshoe Bend as he left to walk his dogs on Jan. 8, 2009. They then forced their way into the home and made the man's wife open the safe before binding her with zip-ties.

The men also held a gun on the couple's 11-year-old son and choked and threatened their 14-year-old daughter, who got away and called police, authorities said. The men left with the money.

A month later, Allen turned himself in. Marino, who was arrested after his sketch was circulated, pleaded guilty in July 2009 and was sentenced to 15 years behind bars.

The third man charged in the incident, James Kaye, planned the attack and theft but did not participate in the acts, authorities said. He was convicted as a party to the crime and was sentenced to 20 years in prison in November 2009.