A man has appeared at the Old Bailey and has admitted killing a university lecturer from Devon.
Daniel Young from Paignton was attacked on his commute to work in London last January.
The court has been told the 30-year-old was stabbed to death as he walked to Morden tube station.
Mark Loveridge was charged with his murder but after months of psychiatric assessments, has pleaded guilty to manslaughter by way of diminished responsibility.
39-year-old Loveridge has a history of mental health problems.
He also admitted causing gbh to 23 year old Kamil Bulat before attacking Mr Young.
Loveridge will be sentenced next month.