DALLAS — A panel of 12 jurors spent two and a half hours Wednesday afternoon before concluding DeLeon Vanegas should go to prison for 18 years for providing a lethal dose of cheese heroin to Fernando Cortez, 15, last year.

Fernando Cortez, Sr., said he was satisfied with the sentence though he hoped it would be more severe.

"I will do my best to make sure he does day for day, 18 years," Cortez added.

"Justice was not served!," said Vanegas' mother, visibly emotional. "My son didn't kill him!

Vanegas' family says they will appeal the punishment.

"My heart goes out to ya'll," Vanegas testified in the punishment phase of his trial. "I'm deeply sorry."

Wednesday morning, a jury convicted Vanegas of delivery of a controlled substance. Jurors went on to find the cheese heroin acted as a deadly weapon in Cortez's death.

Taking the stand in his own defense during the punishment phase of his trial, Vanegas cried when he recalled the fatal car accident that killed his infant son which was prior to Cortez's death.

WFAA-TV

DeLeon Vanegas, right, was found guilty of delivery of a controlled substance to Fernando Cortez Jr.

Vanegas testified his son's death led him to depression and eventually drugs. In fact, the 20-year-old said he even sold cocaine but preferred to take cheese heroin himself.

On cross examination, prosecutor David Alex criticized Vanegas for crying about his own son but not even calling for help when he discovered Cortez dead in his own house. Vanegas admitted he panicked and fled his house instead of calling 911.

This is the first case of its kind to go to trial in Dallas after a wave of cheese heroin related deaths in North Texas over the last two years.

Vanegas was originally charged with murder, but prosecutors changed it to delivery of a controlled substance last month, which still carried up to a life sentence. Prosecutors said they thought that charge might be easier to prove.

Vanegas will now have to serve at least half of his 18 year sentence before he is eligible for parole.

"Hopefully when he comes out he'll be a better person," Cortez, said.