The grandmother of four children murdered in a house fire has accused authorities of "doing nothing", as a police watchdog inquiry resumed.
Michelle Pearson, the dead children's mother, had reported threats against the family to Greater Manchester Police before the blaze.
Their grandmother, Sandra Lever, has asked why authorities failed to act.
The Independent Office for Police Conduct (IOPC) is investigating contact between Mrs Pearson and the force.
Zak Bolland and David Worrall were sentenced to life in prison on Thursday for the murders of Lia, Demi, Brandon and Lacie in December 2017.
Speaking after the pair were sentenced, Sandra Lever questioned why police had failed to act after Bolland's earlier arrest for damaging the family's house in Walkden and said the council refused her daughter's request to be rehomed.
She said: "They all knew about it and they all did nothing about it.
"They dropped the charges, I don't know why."
Miss Lever said Salford City Council had told Mrs Pearson she was not in danger and to "go back home."
The IOPC said it would look into contact between the force and Mrs Pearson in the 16 days before the night of the fire on 11 December 2017, including threats and reports of damage to the family's house in Walkden.
The watchdog's original probe was halted while murder charges were brought.
The trial at Manchester Crown Court heard Bolland, 23, and Worrall, 26, had been involved in a long-running dispute with the victims' 17-year-old brother Kyle Pearson before they threw petrol bombs into the house where the children were sleeping.
Bolland's then-girlfriend Courtney Brierley, 20, was cleared of murder but found guilty of four counts of manslaughter following the blaze.
Greater Manchester Police said it would be inappropriate to comment while an IOPC investigation was ongoing.
Speaking after sentencing on Thursday, Det Ch Insp Lewis Hughes said the IOPC would determine whether opportunities were missed but added: "I don't think anybody could ever have foreseen that this was going to take place during what had been a minor tit-for-tat feud."
Salford City Council has begun a serious case review into its management of the family's request to be rehomed.