A law graduate who studied at St Mary's University, Twickenham, has pleaded not guilty to murdering her boyfriend on the street in Mortlake.

Blaze Lily Wallace, aged 28, is on trial at Kingston Crown Court over the killing of 34-year-old Samuel Mayo.

This week the court heard that the aspiring human rights lawyer stabbed her boyfriend in the heart when he stormed out of their flat after a row.

Wallace graduated from St Mary's University, Twickenham, with a law degree in 2017 and at the time of her arrest was studying her Masters in Human Rights & Legal Practice at the University of Roehampton.

Wallace has pleaded not guilty to murdering Mr Mayo and possessing an offensive weapon - a kitchen knife - in Lower Richmond Road on July 18, last year.

Prosecutor Jane Bickerstaff KC told the jury the couple had been living together six months.

She said: "They were in a relationship and had been living together in her one-bedroom flat in Mullins Path, Mortlake.

"It seems to have been a volatile relationship, characterised by frequent arguments.

"The pair had been arguing on the day of Mr Mayo's death and it seems he had decided enough was enough and he packed a bag and left at about 9.30pm that evening.

"He can be traced on CCTV cameras, following a route away from Mullins Path and towards Mortlake centre and Ms Wallace followed him.

"She can be traced on the same cameras, following the same route, but six minutes behind him.

"A camera pointing onto Lower Richmond Road, from the entrance of the Stagg Brewery captured the pair together, walking past at a few seconds before 9.45pm.

"The defendant had clearly caught up with her intended victim and they disappear off camera to the left of the screen.

"The incident itself is not captured on CCTV footage, but in under thirty seconds Mr Mayo appears back on screen and he is now fatally injured.

"He can be seen to run into the road and back onto the pavement on the other side of the road, where he collapses and died on the pavement."

Wallace admits she followed her eight-stone boyfriend while armed with the knife and stabbed him, but will claim self-defence.

Mayo ran into the middle of the road, shouting for an ambulance and collapsed by a garden wall and was assisted by passing motorist Anais Tolfree.

Ms Bickerstaff said: "She describes his breathing as being shallow and she tried to speak with him, however did not get any response.

"Another member of the public was crouched down by the male talking to him and also received no response."

The court heard that when police arrived at 9.57pm they immediately recognised Mr Mayo as a local drug user, who regularly begged outside Tesco's and Mortlake train station. He was taken to Kingston Hospital and pronounced dead at 10.33pm.

Subsequently, Wallace told the officers she had an argument with her boyfriend and last saw him at Mortlake station at around 10.00pm.

The court heard that a train passenger, Stephanie Slater, witnessed the couple having a row just before 6.30pm that day at Mortlake station. She described the female as the aggressor.

A neighbour, Patricia Blake, also head Wallace shouting at Mayo that day. The prosecutor said: "The female spoke in a really vitriolic, vicious tone and the male seemed to be the appeaser."

The prosecutor said that a Lower Richmond Road resident, Christopher Simpson, heard some of Mayo's last words, shouting: "Please Liz!" up to eight times and: "I love you, please Liz. Please Liz, I love you."

A postmortem revealed a 4cm stab wound had penetrated Mr Mayo's heart, causing rapid blood loss and shock.

Traces of heroin, cocaine and cannabis were found in his blood and the same drugs were found in Wallace's urine, plus methadone.

The trial is expected to last three weeks.