Two young brothers were killed in a hit-and-run by a man who had only been released from prison six days earlier.
Robert Brown admitted causing the deaths of Corey and Casper Platt-May, aged six and two, by dangerous driving on February 22.
The two boys were with their mother in MacDonald Road, Coventry, at around 2pm when a Ford Focus, driven by Brown, ploughed into them.
They were taken to hospital with severe injuries, but Casper could not be revived and died a short time later.
Corey was rushed into surgery, but also later died. Their mother was unhurt.
Brown, 53, had previously been jailed for possessing an offensive weapon and had been let out on licence just six days before the collision.
At Warwick Crown Court, he remained calm in the dock as he entered his guilty pleas despite twice shouting "This is a f****** kangaroo court" and calling the chairman of the bench a "f****** prick" during his magistrates' court appearance.
Brown, of Attwood Crescent, in Wyken, Coventry, remained emotionless as he admitted all charges - including two counts of death by dangerous driving, driving while disqualified, using a motor vehicle without insurance and using a motor vehicle without a licence.
His co-accused, Gwendoline Harrison, 42, denied charges of perverting the course of justice and common assault at the same hearing on Monday.
Adjourning sentencing until April 27 at the same court, Judge Anthony Potter told Brown: "I'm satisfied there's good reason for adjournment in your case. In the meantime you will be remanded into custody."
Tyrone Smith QC, defending, said the presiding sentencing judge would need to watch "troubling" CCTV footage before they passed sentence.
He said: "The mitigation I am likely to put forward is the plea."
The victims' mother, Louise Platt-May, paid tribute to her sons after the collision, describing them as "amazing" and "cheeky" boys who will "be deeply missed".
She said: "Casper was a cheeky little boy, always getting into trouble and driving his brothers crazy.
"But he was so loving and caring and constantly told his family how much he loved them.
"Corey was an amazing boy. He never kept still, always had to be doing something and coming up with new ideas of things to do."