A Lido Beach man convicted of stabbing a 16-year-old to death in Oceanside has been sentenced to 25 years to life in prison.

A jury found Tyler Flach guilty on second-degree murder for using a knife to stab and kill Khaseen Morris during an after-school fight in 2019.

Prosecutors say Flach was apparently enraged that Morris walked a girl home from school and deliberately attacked the victim with a group of seven other defendants.

During Flach's sentencing on Tuesday, there was a lot of emotion inside the courtroom — with the victim's family applauding when the judge handed down the sentence.

The judge denied the defense's motion that was filed last month to overturn the guilty verdict.

Morris' older sister, Keyanna Morris, fought back tears telling the court her baby brother was stolen from his family. She held up a photo of her brother to the courtroom — addressing Flach, saying her brother was full of life before he took that away.

"It feels good to have the judge understand what he put us through, and what he did, and he was held accountable for it," Keyanna Morris says

Flach never turned back to look at her, but shortly after, he did address the court to apologize, saying, "I hate that day, I hate myself for accidently causing the death of your son. I did not try to kill anybody that day. I'm sorry."

The judge told Flach that he is going to "suffer from his stupidity," saying he killed somebody he barely knew. Flach interrupted and said, "We were just kids." The judge responded by saying, "You brought a knife to a fist fight, you are about to learn a very harsh lesson by spending a long time in prison."

The defense told News 12 that Flach's family was disappointed in the judge's sentencing decisions and is prepared for a long appeals process.

"He is not a murderer, he never intended to kill anyone, which is what he said in a statement," says Flach's attorney, Kevin Dunshee. "He is full of remorse for what happened."