13-year-old boy charged as an adult in his mother’s stabbing death while she slept near his newborn sister

 A straight-A student from Florida accused of stabbing his mother to death in her sleep near his 14-day-old half-sister will be tried as an adult.

Derek Rosa, 13, faces first-degree murder charges in the death of his mother, Irina Garcia, 39. Prosecutors said that based on a review of all the evidence, grand jurors in Miami indicted Rosa in an indictment that placed his case into adult felony court.

His father is seeking his release, ABC Miami affiliate WPLG reported after a court hearing on Friday.

“It’s very unfortunate that this tragedy occurred, but this child is very humble, very respectful, and nobody could have imagined that this would ever happen,” Jose Rosa said, the station reported. “He’s a child. Nobody in the house, in the family, sees him as a grown man.”

In an email to Law&Crime, his attorney, Kristen Jackwin, said her client has strong support from his entire family.

“It is important to remember that only two months ago, Derek was a 12-year-old child,” she said. “We have full faith in the criminal justice system and due process of law.”

Rosa called 911 at 11:30 p.m. on Oct. 12, allegedly telling dispatch he stabbed his mother to death, Lt. Eddie Rodriguez told Law&Crime.

Rosa was “so polite” even on the 911 call, Rodriguez said. Everything was “Yes, ma’am; no, ma’am,” he said.

Officers arrived at the apartment, where they arrested him and found Garcia’s body next to a crib, in which lay Rosa’s 14-day-old half-sister. The baby was physically unhurt, Rodriguez said.

Police said the mother, son, and daughter were the only people home at the time, as the stepfather, a truck driver, was in northern Georgia. The Florida Department of Children and Families briefly took custody of the baby, but the maternal grandmother arrived and took care of her until the father could return, Rodriguez said.

All told, there’s currently no indication as to why Rosa allegedly murdered his mother. He did not explain why he killed her, police said.

The murder “left everybody dumbfounded,” Rodriguez said. He called it a “huge tragedy” that left Garcia’s mother without a daughter and Rosa’s biological father essentially without a son.

The lieutenant described Rosa as an 8th grader and honor roll student at iMater Charter Middle/High School. Friends and family described him as a “good kid” and a straight-A student. The teenager had no history of mental health challenges; neither did his family. There were no fights, and he got along with both his stepfather and half-sister, Rodriguez said.

His arraignment is set for Tuesday.