In chilling confession, 13-year-old boy says he stabbed his mother to death while she slept. He will stay in an adult jail

State prosecutors played a chilling tape in court of a 13-year-old confessing to using a purple-handled kitchen knife to slash his mother’s throat as she slept — while his 2-week old sister lay nestled nearby in her crib.

The Hialeah detective who arrested Derek Rosa said he stabbed his mother 46 times, then sent pictures of the bloody scene to a friend he referred to as “Sweden.”

On Friday, the day after the recording was played in court, Miami-Dade Circuit Judge Richard Hersch finally put an end to a lengthy, on-again, off-again, six-week hearing over where the teen will be detained until his trial. The judge ordered Derek to spend the next months or years before trial in an adult jail, not the juvenile detention center that his attorneys had argued for.

“I am disturbed by the relatively small amount of time the child is permitted out of his cell,” Hersch said before his ruling. “But I have not found a clear violation of his constitutional rights — so the motion is denied.”

Still, the buzz in the courtroom remained the previous day’s recording of Derek’s admission of the brutal crime.

“I woke up, I grabbed one of the kitchen knives and I went to her room,” the teen was recorded telling the detective. Then he halted.

“It’s OK, you can say it,” replied Hialeah Police Detective Joseph Elosegui.

“I killed her,” Derek said.

Elosegui told Miami-Dade Assistant State Attorneys Rachel Morales-Gellis and Kathleen Hogue that Derek used his computer to gather information to murder his mother, Irina Garcia, 39. The detective said online searches by the teen included questions about the best way to kill someone and whether a small knife can cut through bone.

After killing his mother, Elosegui said, Derek called “Sweden” and sent him three pictures, two of his mother and one of himself with bloody hands.

Derek, who sat handcuffed in the jury box in a brown jail jumpsuit during the six-week hearing, showed emotion as the tape was played, burying his head between his hands while his attorney, Dayliset Rielo, rested a hand on his shoulder.

Rielo and fellow defense attorney Armando Luis argued to no avail to keep the recording sealed, or out of the public record.

The judge’s ruling came after Miami-Dade prosecutors and Derek’s attorneys heard from a few more witnesses, then delivered closing arguments. During defense attorney Luis’ closing, Hersch stopped him and asked him to come up with a constitutional violation that he could argue would lead to his client being sent to a juvenile jail.

Luis said problems at the adult facility include Derek being served breakfast between 1 a.m. and 2 a.m. each day, that he can’t get his glasses without request and that instructors have been unable to provide specific class schedules.

“He had no contact with his father, no contact with his grandmother or family,” Luis said. “And it was 30 days since being transferred to Metro West without being able to contact his family.”

In her closing, Assistant State Attorney Morales-Gellis took aim at the defense arguments.

“The defense keeps making reference to adult-sized sweaters,” she said. “I don’t think that would rise to a constitutional issue.”

In denying the defense motion to move Derek from Miami-Dade’s Metro West detention center to a juvenile facility, Hersch said the teen’s attorneys failed to prove his time at the adult jail put him in any danger, psychologically damaged him or left him without proper schooling.

Derek served the first two weeks of detention after his Oct. 12 arrest in Miami-Dade’s juvenile-detention center. But after a grand jury indicted him as an adult and upped his charge to first-degree murder he was transferred to Metro West. His defense team then petitioned the court to have the teen placed back in juvenile custody.

With an appeal almost certain, Hersch seemed to go out of his way to give defense and prosecutors leeway in what became an unusually lengthy hearing.

WHY DID HE DO IT?

Though the slaying made international headlines, police and prosecutors have yet to say why the honor student killed his mother. What they have said is they learned of the chilling crime just before midnight on Oct. 12 when Derek called a 911 operator.

When police entered apartment 201 at 211 W. 79th Pl. five minutes later, they found a startling scene: Garcia lay dead on her bedroom floor covered in blood with dozens of stab wounds from a kitchen knife. One of the cuts sliced an artery in her neck. Police said she was asleep when the attack began.

Not far from Garcia’s lifeless body was her 14-day-old daughter in her crib. Derek told police that after he killed his mother, he found two guns owned by his stepfather and wanted to commit suicide, but couldn’t follow through.

Instead, Derek took pictures of his dead mother and shared them with a friend on social media. After taking the pictures, police said, Derek asked the dispatcher if that was “bad.”

Police said the eighth-grader at iMater Middle/High Charter School confessed to the murder to the 911 operator. He didn’t put up a fight when police arrived.

Derek’s case is eerily similar to another that shook South Florida almost two decades ago. Michael Hernandez was arrested for the murder of schoolmate Jaime Gough in the bathroom of Southwood Middle School in Palmetto Bay. Tried as an adult and sentenced to life in prison, Hernandez collapsed and died at Columbia Correctional Institution in Lake City in 2021. He was 31.

The hearing to decide where Derek will stay was halting, with several defense witnesses failing to show up and attorneys often called out by the judge for going off topic. Most of the testimony centered around Metro West’s juvenile-only wing, which employees said usually had close to three dozen teens — though none younger than 16.

Derek’s attorneys said he spent most of his days in his cell by himself, leaving it for about 20 hours during the week for schooling and recreation. Miami-Dade Public Schools teachers who work with Derek at Metro West testified he will received up to six school sessions a week in math, science, social studies and reading of between 90 minutes and 2 1/2 hours.

Derek is currently the only child at Metro West to have a guard seated outside his cell full-time. And when he does leave his cell, guards testified, he is heavily protected. He also has access to a computer, cellphone and a commissary.

Derek has no known mental-health issues and police said they have no record of visiting the family’s home in the Amelia Oaks apartment complex before the stabbing.

If convicted, Derek could spend life in prison. First-degree murder is a capital crime in Florida, but the U.S. Supreme Court has ruled the death penalty is unconstitutional for juveniles.