A Southern California man was sentenced to prison Thursday for rape and sex crimes against his younger sister.

Stephen Delacruz, 37, was sentenced to 30 years in prison for crimes that he committed when he was 14 and 15 years old against his sister, who was 8 years old at the time, according to the Ventura County District Attorney’s Office.

In 2019, the victim, identified as Samantha J., walked into the Oxnard Police Department to report the crimes that took place in 2001 and 2002.

During the incidents, Delacruz isolated Samantha in their Oxnard home and threatened to kill her if she ever reported him, court documents said.

Delacruz often displayed a knife prior to the sexual assaults, authorities said.

Charges were initially filed at the DA’s office in juvenile court, alleging Delacruz was a minor when the incidents happened.

However, Senior Deputy DA Erik Nasarenko sought to transfer the case from juvenile court to adult court, arguing the “crimes involved significant sophistication and planning and were especially violent and severe.”

The juvenile court judge agreed and transferred the case. However in 2022, the state legislature amended the criteria that juvenile court judges had to consider when deciding to transfer a case to adult court.

“The new criteria required courts to determine “by clear and convincing evidence that the minor is not amenable to rehabilitation through the juvenile court,” officials noted.

This prompted a transfer hearing before another Ventura County judge applied the new criteria and deemed the case worthy of transferring to adult court, stating the “allegations were horrendous.”

Before the case went to trial, Delacruz pled guilty to all eight felony charges filed against him including three counts of forcible rape, three counts of forcible oral copulation and two counts of sexual penetration by a foreign object. He also admitted to special allegations that the victim was under 18 years of age.

“Samantha demonstrated great resiliency and determination as she fought for justice and accountability in this case,” Nasarenko said. “Facing her brother during today’s sentencing to give her victim impact statement took incredible strength and courage.”

Delacruz was sentenced to 30 years in state prison.