A man who battered a five-year-old boy to death in a park for losing a trainer has been jailed for life with a minimum term of 18 years.
Marvyn Iheanacho, 39, flew into a rage and subjected his girlfriend's son, Alex Malcolm, to a brutal attack in Mountsfield Park in Catford, south-east London.
He was sentenced at Woolwich Crown Court by Judge Mark Dennis QC, who said the child killer has a "deeply entrenched character flaw" that leads him to overreact and lose his temper.
Iheanacho was sentenced to 18 years but, due to time served on remand, the judge said he would serve at least 17 years and 119 days.
Witnesses heard a child's fearful voice saying "sorry", loud banging and a man screaming about the loss of a shoe.
Alex suffered fatal head and stomach injuries and died in hospital two days later.
One of his trainers was later found in the play area by police.
Iheanacho, who was in a relationship with Alex's mother Lilya Breha, had a "wholly and unnecessary loss of temper", Judge Dennis said.
"The red mist having come down upon you when you discovered that Alex had dropped his shoe," he said.
The judge said Iheanacho did nothing to raise the alarm or to get medical help.
He said it is apparent that Iheanacho, from Hounslow, west London, has a "deeply entrenched character flaw", adding: "One that leads you to overreact and lose your temper."
Judge Dennis said that when the violence had subsided, Iheanacho's thought turned to "protecting yourself and trying to cover up" what had happened.
"Only this time the consequences of your violence were more serious than ever before," he said.
The judge added: "You used your undoubted strength and simple brute force."
He said he was a "strong and overpowering figure" next to Alex who was "completely defenceless", adding: "The child had done nothing that would justify any loss of temper, never mind a violent loss of temper."
The judge said Iheanacho had given fake and misleading accounts to paramedics, hospital staff and police.
"All this to protect yourself and cover up what you had done," he said.
The judge said there has been a "disturbing pattern of sudden and violent behaviour" when Iheanacho is frustrated and not getting his own way.
Iheanacho has a string of previous convictions for violent offences, including attacks on ex-partners and robbery.
The judge said: "Sadly the truth appears to be you simply can't help yourself."
Alex's head, neck and body were covered with bruises after the attack on November 20 last year.
Iheanacho carried the unconscious boy to a minicab office and took him to Ms Breha's flat, while the nearest hospital was just a five-minute walk away.
He then attacked Ms Breha when she tried to call an ambulance, but she managed to grab the phone after noticing her son was getting cold, his face had turned blue and he had stopped breathing.
Doctors at Lewisham Hospital tried to resuscitate Alex, but a CT scan showed he was suffering from severe brain swelling, and he was transferred to King's College Hospital.
He was pronounced dead on November 22 after an unsuccessful operation.
It emerged during the trial that Iheanacho had phoned Ms Breha from prison to pressure her to back him up in court.
"There have been problems with witness interference. The defendant has phoned the mother of the deceased," said prosecutor Eleanor Laws QC.
"We would say pressure is being exerted on the mother of the deceased, with the defendant pressing upon her his defence of accident."
A victim impact statement from Ms Breha, read out in court, said of Alex: "He was a beautiful little angel."
She said: "He was the first person that I truly loved and he loved me."
Ms Breha said Alex was her "purpose for living", adding: "Really, my life ended when Alex's did.
"Nothing will ever be the same without Alex."
A victim impact statement from Alex's father, read out in court, said: "He was a lovely and energetic and playful little boy.
It went on: "I will never forget seeing him in his hospital bed fighting for his life. That image will stay with me forever."
He added that it has been very difficult to keep his emotions in check.
"Just thinking about what's happened and trying to put words on paper is tearing me apart."
An NSPCC spokesman said: "Iheanacho should have been caring for Alex, but instead he violently robbed him of the chance to live a long and happy life. It is right that he is now behind bars.
"Babies and young children are entirely dependent on those who care for them and we all have a duty to look out for their welfare.
"We urge anyone concerned about a child's welfare to call the NSPCC Helpline on 0808 800 5000 as it could save a life."