MILWAUKEE (CBS 58) -- A Milwaukee teen who killed a 12-year-old boy was sentenced to prison on Friday, March 14.

The deadly shooting happened two years ago, during a birthday party in West Allis.

Nineteen-year-old Lawrence Griffin will serve 30 years in prison for killing 12-year-old Ronnel Smith at the Bug 'N' Out Lounge on Feb. 25, 2023.

"I hate to say it, but I want him under the jail," Smith's mother, Quianna Sisson, told the judge at Friday's sentencing.

She says she's heartbroken by the loss of her 12-year-old son due to senseless violence.

"No kid deserves to lose their life. No parent deserves to bury their child," Sisson said.

Lawrence Griffin pleaded guilty to first degree reckless homicide last April.

Security video shows him shoot Smith in the chest during a birthday party at the bar.

"It's terrible. There was probably 50 kids within range there in that room that could have been hurt, killed," said prosecuting attorney Michael Lonski.

The family believes Griffin attempted to steal Smith's prescription glasses before opening fire.

"This is one of the saddest I've seen, because it was something that it could have been avoided, and should have been avoided," said Judge David Swanson.

Griffin's attorney says mental health and anger issues contributed to his already lengthy record.

His mother wrote a letter to the judge, saying she tried many times to get him help.

"She tried to do what she could here, but she feels that he's fallen through the cracks of this system," said Defense Attorney Annette Rauch.

"I hold myself accountable and take full responsibility for my actions," Griffin said in court, apologizing.

Smith's family says 30 years in prison isn't enough.

"I just feel like no sorry, no apology, no time can fix the hurt that we feel," said his aunt, Camille Bowie.

"You got to accept what the judge gives, but I'm still mad as hell," said his grandmother, Aquita Sisson.

Sisson says they buried Smith on his 13th birthday, ten days after he was killed.