Blake Leibel, 37, was sentenced in the death of Iana Kasian in 2016. Leibel was found guilty last week.
Judge Mark E. Windham cited Leibel's "profound brutality" when he handed down the life term.
The victim's mother, Olga Kasian, delivered an emotional impact statement in court before the judge read the sentencing.
"There are no words to express the pain and despair in my heart. I never thought that one day my life would be broken. For two years I've been asking God and myself, 'Why? Why did my daughter have to endure this inhumane torture and suffering?' Because she wanted to laugh and to love? Because she wanted to have a baby and have a family?'" Olga Kasian said with the help of a Russian translator.
WARNING: Details in this story may be graphic for some readers.
The couple lived together in West Hollywood, and Kasian had given birth to their child weeks before her death.
Prosecutors said the gruesome murder followed a script from Leibel's graphic novel, "Syndrome," featuring a baby with its skull partially removed.
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Investigators said Kasian had been found in her bed, apparently suffering from blunt force trauma to the head. Authorities said Kasian was tortured and mutilated before she was killed, and all of her blood was drained from her body.
Graphic details in the recently released report also indicate that her scalp was missing, leaving her skull fully exposed. Her scalp was never found.
The report indicates the scalp had been cut at the back of her head, but in other areas it appeared to have been ripped away. The report also stated portions of the right side of her face were torn off, including her right ear.