Tributes have been paid to a mother and her two children who died at a tower block in Luton.
Bedfordshire Police said it believed the victims to be Juliana Prosper, 48, Kyle Prosper, 16, and Giselle Prosper, 13 - all of Leabank - but formal identification was yet to take place.
Nicholas Prosper, 18, also of Leabank, and named locally as Ms Prosper's son and sibling to the child victims, has been charged with murder and a number of firearm offences.
In reaction to an online police post about the charges, one woman wrote: "It is so heartbreaking - my son was a close friend of Kyle - he was a lovely, smiley, quiet boy."
She continued: "It’s so hard to believe this has happened to him and his family."
Another person posted: "My daughter has been in Kyle's class throughout her school life - it’s so hard to believe. RIP Kyle, Juliana and Giselle."
Someone else also wrote about their memories of Kyle, describing the incident as "devastating news".
"Kyle was the loveliest lad you could wish to meet," they continued.
Flowers and cards have been left at the entrance to the Leabank block of flats, in the Marsh Farm area of Luton.
Officers were called to the flats at around 05:30 BST on Friday and found three people with fatal injuries.
Bedfordshire Police said Mr Prosper, 18, was arrested shortly after officers were called to the property.
He was charged on Saturday and is due to appear at Luton Magistrates’ Court on Monday.
A firearm was found during a search of the surrounding area, the force confirmed.
On Saturday, Det Supt Rob Hall, from the region's major crime unit, said officers who arrived at the scene were "met with such awful circumstances".
He continued: "First and foremost, our thoughts are with the three people who sadly lost their lives yesterday and their loved ones.
"Although formal identification has yet to take place, next of kin of those who we believe to have died have been informed and are being supported by specialist officers.
"We would ask that their privacy is respected at this unimaginably difficult time."
He added that officers would remain at the tower block while the investigation continues.