A driver whose car hit another in a head-on crash, killing his five-year-old stepson, has been jailed for six years.
Joseph Smith was not in a booster seat and suffered multiple injuries when the car he was in smashed into oncoming traffic on Cardiff's Western Avenue.
Dean Collins was found guilty of causing death and causing serious injury by dangerous driving on Tuesday.
The 24-year-old, from St Mellons, was sentenced at Cardiff Crown Court.
He was also handed a three-year sentence for the serious injury charges, which will run concurrently, and has been banned from driving for eight years.
The Recorder of Cardiff, Eleri Rees QC, told Collins: "You have never acknowledged any fault despite overwhelming evidence it was entirely your fault.
"The obvious inference is that you allowed yourself to become distracted.
"The general manner of your driving was impatient and a general disregard for road safety."
She said he also showed a "blatant disregard" for the safety of his four passengers, had shown arrogance and an aggressive manner of driving immediately before the crash.
The judge criticised his "cavalier attitude" to both his own safety and that if others, adding the lack of a car booster seat had contributed to Joseph's injuries.
The trial heard Collins - who had denied all the charges - was driving a borrowed Ford Focus carrying his partner Laura Bright, 23, her mother Michelle Holmes, Joseph, and the couple's two-year-old daughter at the time of the crash.
The car crossed a central reservation on Western Avenue and slammed into a white Seat Ibiza heading in the opposite direction.
Collins' driving before the collision had been erratic, with the car weaving in and out of traffic and undertaking other vehicles.
Blood samples taken from Collins after the collision contained traces of cocaine.
But the quantity was too small to accurately measure and a toxicologist said it was not possible to say how the drug would have affected Collins' actions.
Collins, who had passed his driving test just three months before, said he had no memory of the crash and insisted it was a "tragic accident".
Four others suffered injuries in the crash, including fractures to the spine, arms, legs, ribs, memory loss and blindness in one eye.
Joseph's mother Laura Bright, who has since married Collins, was unconscious for five days after the crash.
She was cleared at a previous hearing of causing the death of a child in her care.
The court heard she was now pregnant with his third child.
South Wales Police investigating officer PC Tony Farr, of the Serious Collision Investigation Unit, said the crash had had a "devastating impact on so many lives".
"I cannot stress enough how dangerous vehicles can be when they are in the hands of the wrong people," he said.
"Collins was inexperienced and evidence presented to the court showed he had taken drugs in the days or hours before the collision. Tragically, that proved to be a lethal combination.
"Collins also failed to ensure Joseph was seated securely in the vehicle - again a huge error in judgement that he will now have to live with for the rest of his life."
Speaking after the hearing, Joseph's father, Tom Smith, said of the crash: "It's traumatised me, I don't sleep, all I do is think about that little boy."
Ann Haile of the Crown Prosecution Service said: "This case is a stark reminder of how dangerous moving vehicles are when they are not controlled properly, and how important it is for children to be in a suitable, properly fitted car seat."