A 24-year-old woman died in a suspected stabbing in Hayes, west London, on Sunday morning.
Emergency services were called to Uxbridge Road at around 7:55 am, and the woman was pronounced dead at the scene.
Dramatic footage obtained by Metro appears to show a man knocking at the door of a nearby house, brandishing a large knife.
Metropolitan Police said they quickly found a 44-year-old man nearby who matched the description of the suspect, who had injuries believed to be caused after jumping from a window.
The suspect was taken to hospital, and a man has been arrested on suspicion of murder and possession of a knife in a public place.
There is no thought to be any wider threat to the public, but officers said people in the area can expect to see more police in the area over the coming days.
A neighbour described the victim as a "friendly, smiley young mum" who doted on her newborn baby.
The air ambulance responded to the scene, and detectives and forensics officers are now scouring the area.
Local MP John McDonnell said the murder was a "terrible tragedy in our community".
Detective Chief Inspector Allam Bhangoo of the Met said: "This is a shocking incident which has tragically resulted in one woman losing her life and another man in hospital with injuries.
Our thoughts at this time are with both victims and their loved ones, who are being supported by specialist officers."
A large emergency response was seen at the scene, with police cordoning off the road and forensic officers collecting evidence.
Shop owner Ram Chandra described the scene as "carnage" and said he saw a man in the road badly injured.
A mother-of-two, who lives nearby, said she is too scared to let her children play outside after the attack.
The police are urging anyone with information to come forward.
Residents in the area are being supported by specialist officers, and the police are working to keep the community safe.
