A boy who took revenge for being dumped by starting a house fire which killed his ex-girlfriend and her sister has received a life sentence.
Akmol Miah, 15, was found guilty of murdering Maleha, 15, and Nabiha Masud, 21, who died after the fire in Tooting, south London, last June.
At the Old Bailey the teenager, from Croydon, south London, was sentenced to a minimum term of 23 years.
The sisters' mother and two brothers were also injured in the fire.
Miah's cousin Shihabouddin Choudhury, 21, of Nottingham, was convicted of the same charge and jailed for life.
Choudhury was told he must serve at least 21 years in jail.
During the trial, the court heard how Miah, who was 14 at the time of the fire, had searched on Google for "how to burn someone's house down" the day before the fire.
He saved a picture of the gutted house as his mobile phone screensaver.
Miah had previously threatened Maleha that if she did not continue their relationship he would "do something to her and her family".
Judge Christopher Moss told him: "These dreadful events happened for no better reason than that you wanted to inflict revenge on Maleha and her family for the fact that she ended your relationship.
"I am faced with a boy who, at the age of 14, planned and carried out this murderous attack and who is still in denial."
Judge Moss said the pair had remained in the area after the attack, "no doubt to witness of the results of your dreadful actions".
He added that the killers "might well have succeeded in wiping out the entire family".
The teenager recruited his cousin Choudhury, a waiter, to help start the blaze by pouring petrol through the Masud family letterbox and setting fire to it as the family slept.
Jonathan Laidlaw QC, prosecuting, said Maleha's relationship with Miah had not been a serious one.
He said: "Why he should arrive at the extraordinary decision to burn down their house is really impossible to understand.
"It was obviously not the reaction of an ordinary and normal 14-year-old, however hurt he might feel about losing a girlfriend."
In a victim impact statement, the girls' mother Rubina Masud said: "There are no words that can highlight the crippling grief, pain and agony that I am experiencing.
'Damaging, evil, cold-hearted'
"They have given me a life sentence. What did we do to deserve this?
"What caused such hate for the perpetrators of this to carry out such a damaging, evil, cold-hearted and malicious attack?"
Mrs Masud said she lost all her childhood photographs of her daughters in the attack.
Zain Masud, the victims' brother, said of Miah: "He sat there blank as though he's convinced himself nothing's happened."
He added: "I don't know what type of sane person would imagine it - even if you hate someone.
"It is hard to contemplate why anyone would do such a thing."