JACKSONVILLE, Fla. -

A 17-year-old who pleaded guilty to murder in the death of a 13-month-old girl was sentenced Friday to life in prison without parole.

Javarris Lane pleaded guilty in September to second-degree murder, aggravated child abuse and sexual battery on a child younger than 12. He was sentenced to two life terms.

Lane, who was 16 at the time, was watching Alexandria Williams, who belonged to his mother's friend, at his home on West First Street in September 2011 as their parents went to the store. That's when investigators said he shook the crying toddler, hit her head multiple times on a dresser and sexually abused the girl. She died days after her injuries.

Lane initially told investigators the baby fell off a bed, but then admitted to beating the child. His defense attorney said he had an anger problem and couldn't control himself.

But after an autopsy, evidence came out that Lane not only killed the girl but sexually assaulted her first, something police said made it clear this wasn't an accident.

Javarris Lane & Alexandria Williams Alexandria's family couldn't hold back tears as they talked about what happened at the sentencing hearing.

"I miss my daughter and I shed tears when I think about her or look at her pictures," Alexandria's mother, Sharnell Johnson, said. "This is the worst pain I have ever experienced. I prayed and cried for a miracle every day."

Alexandria's father, Robert Williams, also took the stand at the hearing.

"All I ask of the court is to do what I can't, and that's to see this predator never hurt another family again," Williams said to Judge Adrian Soud.

The teen's mother broke out screaming and crying when the judge handed down his sentence. Soud said he could have no mercy on Lane.

"Mr. Lane, you cannot blame your mother, you cannot blame ADHD," Soud said in sentencing the teen.

"People say that everything happens for a reason. But that's a lie," Williams said. "Sometimes things just happen for no reason."

Alexandria's parents do agree the punishment is what Lane deserved.

"I don't hate him, but I don't have no forgiveness in my heart for him either," Johnson said. "I don't know if I'll ever forgive him."

"I have never hated anything or anyone," Williams said. "I can no longer say that."