Police in Wolverhampton have confirmed that a man stabbed his sister to death and critically injured his mother before turning the knife on himself.
Melvin James is understood to have killed his sister Anne-Marie in a block of flats in the West Midlands city.
Ms James has not yet been named officially by police but flowers have been left outside the flats and tributes have been left for the pair on Facebook.
Djmario McKetty-Campbell said: "Rip Melvin and Ann-Marie (sic). Love and condolences to the family."
Vanessa Duncan added: "RIP Ann Marie and Melvyn (sic). Such sad news. Thoughts are with the family".
Officers used stun grenades as they stormed the first-floor flat in Highfield Court, in the Merry Hill area, and attempted to subdue the knifeman on Wednesday morning.
Ms James, 33, died at the scene while Mr James, 36, was pronounced dead shortly afterwards.
The siblings' 59-year-old mother was taken to hospital where she underwent surgery for serious stomach injuries. It is understood she is still being treated for her injuries.
Two police officers also needed treatment, although neither was seriously hurt. One was stabbed in the arm and the other suffered a leg injury while being chased by the attacker.
Unarmed officers who initially attended were reported to have unsuccessfully attempted to deploy their Taser, before calling for armed backup.
Forensic investigators spent much of the day at the scene on Wednesday.
The attack has been referred to the Independent Police Complaints Commission (IPCC) and post-mortems are due to take place on Thursday, police said.
IPCC commissioner Derrick Campbell said: "These were traumatic events in Wolverhampton... and my sympathies go out to all those affected.
"Our investigators are now busy conducting initial inquiries to gather a full picture of the police involvement in what unfolded.
"It is proper that in such a serious incident as this there is independent scrutiny of what took place."