Grandma of Hialeah teen accused of killing mom says her pain ‘will never pass'

Isabel Acosta's modest apartment opens up to a photo of her daughter, Irina Garcia, which hangs over a small table with flowers, a glass of water, a lamp perpetually on, and an urn, that holds Garcia's ashes.

Acosta aches for her daughter, who was allegedly stabbed to death in her sleep by her own son, Derek Rosa, in October 2023 in their apartment in Hialeah. She was just 39, and Derek, 13 years old.

Nearly two years after the heinous murder that shook the community, Acosta broke her silence with NBC6 sister station Telemundo 51.

"I was left without a daughter, without a granddaughter, and I'm without my grandson... that angel that I've never been able to see since," she said.

Acosta is talking about Derek, now 14, who police say called 911 to confess to the crime. He faces a charge of first-degree murder and is currently being held at Metro West County Jail, an adult facility, awaiting trial.  

The teen's grandmother describes her pain as permanent. Her life, she says, starts at 8 p.m. every single night, when she talks to Derek for 15 minutes. His biological father gets the next 15.

"I'm the same as I was in the beginning. I feel the same. This will never pass," she says. "I would like to [visit him], but I don't think I can."

Acosta did not answer questions about the case during this interview. Instead, she spoke about what life has been like since her daughter's killing.

She recalls out the graphic images of the lifeless body of her daughter that have circulated on social media after her death.

"That's like salt in the wound," she said. "They don't think that there's an angel, a boy, behind bars, and my daughter, who isn't here anymore... that's a pain you have to feel to understand."

Since the crime, police have also released bodycam videos of Derek's arrest, along with interviews they conducted with him and Acosta.

Acosta also speaks of her heartbreak over her granddaughter—the newborn who was lying in a crib next to Garcia during the attack. She is now with her father.

"I haven't seen her since," she said, choking back tears. "They took her from me the 28th of October... It's a very bad memory."

Jose Rosa, Derek's biological father, also spoke to the media for the first time alongside Acosta.

"Not being able to hug my son, I know the importance. The role of a father, to give him a hug, teach him, support him, have a future with him as a young man, and not be able to hug him and give him a kiss," Jose Rosa said in Spanish.

As the case pushes forward, so does the family, present at each hearing. They've let their silence, pain and persistent presence be a beacon of hope and light, like the light that Acosta still sees in her grandson.

"Everyone who knew him, he was a child, he is an exceptional child, very intelligent, very good," she said of Derek. "I'm going to continue until the end."