Justin Blackshere was sentenced Friday morning to life without parole for the Jan. 2 slayings.
The former busboy at Cheli's Chili Bar was convicted last month on two counts of first-degree murder in the deaths of chef Mark Barnard, 52, and restaurant manager Megan Soroka, 49.
Judge Helen Brown called Blackshere "pathological" before announcing his sentence.
"You are the most cool-blooded killer I have ever seen," Brown said. "I'm grateful you will not be able to hurt anyone else."
Blackshere had been fired twice - the final time in November - and told investigators he went to the downtown restaurant to get his job back. He stabbed Barnard 28 times with a cooking knife after being told to leave. He then stabbed Soroka 14 times before fleeing with about $10,000 from the restaurant's safe.
Blackshere was videotaped by a security camera, recognized by former co-workers and was wearing a bloody shirt when arrested later that day. He thanked his family Friday for not giving up on him and told relatives of his victims that he was sorry for their loss.