A man has been charged on suspicion of murdering Daniel Young, who was stabbed to death near Morden tube station on 19 January.
Mark Loveridge, 37, of Borough Road, Mitcham, appeared via video link at Bromley magistrates' court on Friday.
Loveridge was arrested on suspicion of murder on Tuesday and was remanded in custody at a south London police station, the Met confirmed.
On Tuesday 19 January police arrested a 26-year-old man on suspicion of wasting police time and on suspicion of murder. On Thursday 21 January a 35-year-old man was also arrested on suspicion of murder. These two men have been released on bail.
Daniel Young, a 30-year-old university lecturer, was killed at around 8am as he was making his way to his new job.
Police said it was an "unprovoked attack on a man that was simply going about his daily business".
On Thursday, findings of a postmortem determined the cause of death as a stab wound, though police would not provide additional details.
It would have been Young's second day working at Coventry University's London Campus International.
The Metropolitan police released CCTV footage of the last moments before Young's death.
Police are also investigating an incident that took place 40 minutes before Young was attacked in which a 23-year-old man was stabbed in his buttocks. The injuries were not life-threatening.
Detectives are working to establish if there is any evidence that the same suspect has committed both attacks, police said; however, the two incidents have not been linked "forensically or evidentially".
In a statement released on Tuesday, DCI Cliff Lyons, who leads the investigation, reassured the public and urged anyone with information to come forward.
"I would like to reassure people, particularly the residents of Morden, that attacks of this nature are rare," he said,
"Uniformed police officers from Merton Borough continue to patrol the area and provide a visible reassurance to the community."
Fiona Rutherford is a reporter for BuzzFeed News and is based in London.
Contact Fiona Rutherford at email@example.com.
Got a confidential tip? Submit it here.