Michael David Balderas, 33, did not make a statement before Judge William Froeberg handed down his punishment. He was found guilty of second-degree murder and child assault causing death on Jan. 25.
Authorities say Balderas had received custody his niece, identified as Baby Jo Jade, because his sister was preparing to serve a federal prison sentence. Balderas physically abused the child between January and March of 2006, prosecutors said.
Jo Jade bled to death on March 30, 2006, after Balderas repeatedly beat her with his hand and belt.
Balderas' girlfriend Shannon James testified during the trial that on the day the toddler died, a panic-stricken Balderas had called her and asked her to rush home without explaining what happened.
When she got home, Balderas had the girl in his arms and the two drove to the hospital while James called 911. While James was on the line with a 911 dispatcher, Balderas told her, "Hang up the phone, I'm going to jail for this," James testified.
Nurses and physicians testified that the child suffered anal and vaginal tears and that her DNA was found in a swab taken from Balderas' penis.
Though no sexual assault charges were brought, Deputy District Attorney Mike Murray alleged the defendant "tortured and sexually assaulted the child over a five-hour period."
"His behavior was monstrous and the evidence was overwhelming," Murray said after the sentencing.
The prosecutor said a motive for the crime was elusive.
"A lot of times (with) murders -- as senseless as they are -- you can at least determine a motive. But in this case, the motive was the defendant's sexual interests and uncontrollable anger, which is no motive at all," Murray said.
City News Service contributed to this story.