Two women, believed to be mother and daughter, were left fighting for their lives on the side of the road after being brutally attacked by a stranger at Adderley Gardens, Greenwich, in south-east London.
The Met Police said that the two women, believed to be aged 64 and 30, were found with injuries 'consistent with a violent assault' after being reported to the scene at 12:10 pm on Sunday at Adderley Gardens, SE9.
"A hammer has been recovered by officers and police believe this may have been used in the assaults," said Scotland Yard. "Both victims have been taken to south London hospitals where they both remain in a critical condition."
Nearby neighbour Bob Gover, 69, said that he heard screams outside the window of his flat. "I went out there and I saw blood on the face of one of them and I knew something had happened so I ran inside and phoned for an ambulance.
"One of them was moving at the time and sitting in an upright position with somebody holding her up, while the other one was laying down. They were both covered in blood."
Another witness described the man 'calmly' swinging the hammer as his victims lay bleeding on the ground. "I heard screams, it sounded like kids.
"And there he was swinging his hammer. He was so calm."
She commented that he started hitting a brick wall before he 'got on his pushbike and calmly cycled away from the scene'. She said the two victims are not believed to live locally and were visiting friends in the area.
The police announced that the man, Joe Xuereb, 27, was arrested at 7:35 pm in Old Farm Avenue, Sidcup, "as a direct result of the media appeal; police received a number of calls and one member of the public followed the man in her car until police had detained him."
He was arrested on suspicion of two counts of attempted murder.
Detective Superintendent Jane Corrigan said: “I would like to pass my thanks to the public and the media for all their support. I am extremely proud of my colleagues and the community, who have all done so much to bring this part of the investigation to a safe resolution. It shows what can be achieved when we all work together.”