A man who murdered two women on Christmas Day has been jailed for life, with a minimum term of 39 years.
Jazwell Brown had previously pleaded guilty to killing Teohna Grant and Jo Pearson in Milton Keynes last year - as well as two counts of attempted murder.
Detectives say the attacks were wholly unprovoked and committed while he was under the influence of crack cocaine.
Brown had fatally assaulted Ms Pearson - his 38-year-old partner - in their home by stabbing her repeatedly and beating her with a baseball bat.
He also attempted to kill his 18-year-old son, Jake Brown, using the same weapons.
The 49-year-old then took a knife and the baseball bat to his neighbour's flat, where he killed 24-year-old Teohna Grant.
Her partner, Bradley Latter, sustained more than 20 injuries to his neck alone, but survived.
Brown also stabbed Ms Pearson's dog before fleeing the scene in his car - driving at dangerously high speeds before he was arrested.
Footage from a nearby doorbell camera showed the dog walking around while bloodied and injured.
Detective Chief Inspector Stuart Brangwin says the scenes faced by emergency services that evening were "indescribable".
He added: "The events that unfolded on that day were truly horrific and tragic. We may never know what prompted Brown to behave the way he did."
Beyond the life terms for the murders of Ms Pearson and Ms Grant, Brown was sentenced to 18 years for the attempted murder of his son - and 21 years for the attempted murder of Mr Latter.
He was also sentenced to nine months for attacking Ms Pearson's dog, and 18 months for the possession of a knife in a public place.
The judge said all of the sentences will run concurrently.
Luton Crown Court heard that Jake Brown described his father as being "completely expressionless" as he attacked them.
The teenage boy called the police as he hid in the bathroom before Brown breached the door - holding the baseball bat.
Jake told officers there had been no argument and nothing to justify the defendant's actions, and that the attack was like "watching a horror film", prosecutor Deanna Heer said.
Brown then made his way across the communal landing to the flat next door, where Mr Latter and Ms Grant, who had left their door unlocked, were sitting in the living room enjoying a quiet Christmas Day.
Ms Heer said Brown stabbed them both multiple times with a "blank" face.
A bloodstained knife was found on the passenger seat of his car, with the defendant's fingerprint in blood on the knife, while spots of Ms Pearson's and Mr Latter's blood were found on his trainers.
In a statement, Ms Pearson's family said: "Jo was a loving daughter, sister, mother, auntie, cousin, friend and neighbour. Her life was needlessly and cruelly cut short in horrendous circumstances on Christmas Day, in her own home at the hands of her partner. We will never be able to understand why."
Meanwhile, Ms Grant was describe as someone who had "a huge heart full of love and kindness".
"As a family we are heartbroken to have lost her," they said. "The heartbreak is intensified by the realisation that we lost her due to the senseless, cruel actions of someone else. Our world is emptier, full of sadness and holds a lot less laughter now that she has gone.
"Teohna deserved more time to live and deserved the chance to experience the good things life still had to offer her. The world is a darker place without Teohna's beautiful smile."