Alice Gross case murder suspect Arnis Zalkalns profiled
Charges would have been brought against Alice Gross murder suspect Arnis Zalkalns if he had lived, Scotland Yard has said.
BBC News takes a look at who Arnis Zalkalns, a convicted murderer, was.
Described as a "threat to society", Mr Zalkalns's body was discovered just a 20 minute walk from where Schoolgirl Alice was found dead.
The 41-year-old Latvian had hanged himself from a tree in Boston Manor Park. He was last seen on 3 September, a week after Alice went missing.
The search for both Alice and Mr Zalkalns was the biggest police search operation since the terrorist attacks in 2005.
Mr Zalkalns was filmed on CCTV riding a bike along a canal towpath 15 minutes after Alice walked past the camera.
At the time she went missing, he was working as a labourer on a building site in nearby Isleworth.
He is believed to have moved to the UK in 2007, after serving a seven year jail term for the murder of his wife, Rudite.
Latvian court documents about the 1998 murder case reveal a psychologist assessed Mr Zalkalns as being mentally stable and said he knew exactly what he was doing when he murdered his wife and buried her in a shallow grave.
In a confession Mr Zalkalns - who took his wife's surname - told police his wife had told him she was a lesbian and started regularly going out without him.
One night when she did not return home, the experienced welder made a metal pole and an eight-inch knife, which he used to hit and stab her, he said.
After killing her he smoked a cigarette and went home, sleeping for two nights, before reporting her missing to police.
Latvian court documents contained details of medical notes detailing how, in 1995, Mrs Zalkalns was shot in the stomach.
No-one was convicted in that case, but Mr Zalkalns' former mother-in-law, Viktorija Zalkalns, blamed him. He claimed his wife had tried to kill herself although she said she was shot by passing teenagers.
Since Alice's disappearance Ms Zalkalns has said: "He's a threat to society - if he's done this to one person, he could probably do it to another."
She added: "A person like that is sick. He should be put into a hospital. If someone does something like that completely drunk and he's so jealous that he can't control his feelings, then you could also forgive him.
"But doing it consciously with a clear mind and waiting for the moment to do your dirty work, that I can't understand."
As the search for Alice intensified, Mr Zalkalns's brother Janis Daksa said he had been made to look like a "monster, a villain".
"What I know and what I have read, differ. No-one is interested if he is a good man," he said.
"Everyone is looking for a sensation, where he is shown as a monster, a villain. That's what they want."