Watts pleaded guilty to all of the charges against him: five counts of murder in the first degree; three counts of tampering with a deceased human body; and one count of unlawful termination of pregnancy.
Shan'ann's family also spoke at the sentencing, providing emotional statements as Watts kept his head down and avoided eye contact.
Police charged Watts with multiple felonies on August 20 after Shanann - 15 weeks pregnant - disappeared along with the couple's 3- and 4-year-old daughters in Frederick, Colorado. The bodies of Bella and Celeste were found in commercial oil tanks at a company where Watts had worked.
Shanann Watts, 34, and her two daughters ages 3 and 4 were reported missing.
The court heard Watts' pleas and happy photos covered up the fact he was having an affair with a colleague and making plans for a new life when he killed the family he appeared to love. Police have said Watts then drove their bodies to an oil site owned by his former employer.
Court records revealed that Watts acknowledged to police that he killed his wife.
Shanann returned home to Frederick, Colorado, from a business trip in the early hours of August 13.
Shanann Watts' family members "were very strongly in favor of a resolution in this case short of the death penalty", Rourke said. "I didn't want death for you because that's not my right", Shan'ann's mom said through tears.
Mrs Watts was strangled, but her lack of significant injuries suggested her death came slowly, he added, as her father Frank Rzucek leaned forward and gasped.
Amazon hit by data breach before Black Friday
Last year, Amazon recorded a profit of almost $2 billion during its fiscal quarter covering the holiday season. Today's Amazon email leak notification comes after the company sent out a similar notification last month.
Spain to vote against Brexit accord if text on Gibraltar not changed
Gibraltar, a strategically important peninsula on its Southern Coast, was ceded to Britain in the 1713 Treaty of Utrecht. In this, Madrid - traditionally a supporter of the European Commission's policies - has surprised many in Brussels.
Is Theresa May risking a Hotel California Brexit?
The important thing is that we're here for our constituents and as prime minister I'm here for the people of this country. But there was still no certainty over the extent of the revolt against Mrs May's leadership in the Tory ranks.
Christopher Watts was sentenced Monday, almost two weeks after pleading guilty to avoid the death penalty.
The 33-year-old will not be eligible for parole.
Days later, after local police called in the Federal Bureau of Investigation, he was charged with killing his family.
In an interview with The Denver Post, Kessinger explained that they had met at work in July and Watts did not wear a wedding ring.
He called his sister his "best friend" and said his brother-in-law "took away my privilege of being an uncle to the most precious girls".
"Prison is too good for you", Mr Rzucek said. I don't know how, the cameras don't lie. "Your children loved you to the moon and back", Sandra Rzucek said, still holding her composure. When she inquired further, she learned he had children and he allegedly told her that the divorce was mutual and nearly final, according to the newspaper.
She peppered him with questions via phone calls and text, she said, and he changed his story about the divorce, showed little emotion about his family's disappearance, and tried to change the subject. Watts will spend the rest of his life in prison.
As the girls' grandparents, Watts' parents, Cindy and Ronnie Watts, were allowed to speak, each saying they still loved their son and urging him to seek God's forgiveness.
"When I read the news, I found out he was still married and his wife was 15 weeks pregnant", Kessinger told the newspaper.