The jury in the trial of a man accused of murdering his ex-girlfriend in a shopping centre car park in Chatham has been shown footage of the moments before and after the attack.

Joshua Stimpson, 26, from Wouldham in Rochester, stabbed Cobham student Molly McLaren, 23, to death at the Dockside Outlet centre last June after she broke up with him, Maidstone Crown Court was told yesterday.

Today, CCTV images of Stimpson buying the knife at Asda in Chatham two days before the killing were shown to the court, as well as further footage of Molly and Stimpson at the gym minutes before the attack.

Scroll down for video. Warning: readers may find footage upsetting

Wearing shorts and a top, Molly entered the gym first and started exercising. Stimpson, wearing his gym kit, entered afterwards and exercised near her.

After seeing he was there, Molly went over and spoke to him. They both continued exercising before Stimpson left first.

While there Molly contacted her mother and friends. She is last seen walking out of the main doors to the car park.

The footage then cuts to police arriving. Stimpson is shown with his hands on the bonnet of a police car before being arrested.

Prosecutor Philip Bennetts QC said there was a “carefully considered purchase” of the knife and he then went to the gym knowing Molly was there.

He added it was “careful and considered with the execution of Molly”.

Mr Bennetts said of when Molly left the gym: “By this time the defendant must have been waiting for her to come out. He drove slowly along waiting for the moment he must choose carefully to kill her.”

The jury, he said, would hear evidence next Thursday from two psychiatrists. Judge Adele Williams would give a direction that would assist.

Dr Philip Joseph, for the prosecution, would state it was not a case of diminished responsibility.

“It is a case where you can be satisfied so you are sure the defendant is guilty of murder,” said Mr Bennetts. “You decide that on the evidence you hear.”

Stimpson's QC Oliver Saxby stated at the close of the prosecution opening of the case: "None of the evidence the Crown is going to call is in dispute.

"We will not be saying to any of the witnesses they have got it wrong. My role is to place in front of the jury any evidence about his state of mind, which will be referred to next week."

Earlier today, a woman Stimpson struck up a friendship with told the jury how she found all four tyres on her car slashed after he said: "There will be a surprise waiting for you when you get home."

He also told the woman, Alexandra Dale: "If you ever touch my family I will stab you."

Giving evidence by TV link from Newcastle-under-Lyme, Miss Dale confirmed she contacted the police after hearing Stimpson had been accused of murder.

He had sent her a friend request on Facebook in 2013. After six months of contact they met up in a pub in Newcastle-under-Lyme. She went with a friend.

“He told me not to speak to any of my male friends there because he didn’t like it,” she said.

Asked how Stimpson appeared, she said: “A bit uneasy, a bit on edge. I felt a bit wary. I didn’t know what was up with him.”

Afterwards, he texted and rang her. Some days she would have as many as 25 missed calls from him.

“To start off his messages were normal,” she continued. “Then he got a bit possessive and wanted to know where I was. He would take pictures of me and ask why I was wearing such clothing when I was out.

“There were possessive texts calling me a slag. He used to just follow me when he took pictures. It came as a surprise to me. I didn’t even know he was in the same club as me.”

She had not told him where she lived but in July 2013 he sent her a picture of her back garden.

Another time she was in a nightclub and she discovered he was there.

“He grabbed my wrist and told me he was going to tell my ex-boyfriend I slept with his brother,” she said.

Asked if she had, she replied: “No. I didn’t understand why he said that to me. My ex-boyfriend contacted me and asked who Joshua was and why he said this. I just told him who he was.”

She would see Stimpson driving past the house. While she was on holiday he texted her: “I am going to fly out and drown you.”

“He was threatening me,” said Miss Dale. “I didn’t know what I had done to cause him to do that. I am sure he just made up stuff.”

It was after she went to a party and she told him to stop calling her that he told her there would be a surprise for her at home. She contacted her mother to make sure everything was OK.

When she arrived home at 4am she saw that her tyres had been slashed “from top to bottom”. Later that day she saw his car drive slowly past.

“I contacted the police straight away,” she said. “There came a time a couple of weeks after that all communication stopped. I didn’t know if it was because he got warned by the police, but it stopped.”

Mr Saxby told Miss Dale he would not suggest anything she had said was wrong, adding: “Everything you said is no doubt correct.”

Miss Dale said during the year-long contact, Stimpson claimed he lived in her area, but she found out he had driven from Kent.

She agreed with Mr Saxby that it was fair to say Stimpson was “a little bit obsessed”.

“He would send messages and phone me several times a day,” she said. “The messages became stranger with threats and comments.”

Mr Saxby said: “You mentioned when your tyres were slashed and you saw him driving past. It isn’t rocket science to put two and two together.”

Asked by the jury why there were so many people in the dock with Stimpson, Judge Williams explained they were dock officers and medical staff as he was being accommodated in hospital.

“That doesn’t prejudge the issue you are trying,” she stressed. “It won’t affect your evaluation of him.”

Lynn Cox reported live from the second day of the trial. Here is how the hearing unfolded.

[Live Grid - Trial updates 2]