A man involved in a deadly Kahala robbery in 2010 was sentenced Monday to 30 years in prison.

21-year-old Zachary Robinson was convicted of attempted murder in the first degree, manslaughter, and assault and burglary charges.

Robinson and his friend, Cody Mikami, entered Mary Lee Koskinen's home, robbed it, then beat Koskinen and her caretaker, according to prosecutors.

"The 84-year-old Koskinen came out of the room, saw what was going on at that moment," said prosecutor Adrian Dhakhwa.  "The plan came to shut them up, to shut her up and that resulted in her getting beaten to death."

Mikami was sentenced last week to 20 years in prison for his role in the attack.