The sixth suspect in the racist murder of Stephen Lawrence tried to stab a black security guard while saying he had killed before, the OceanNewsUK can reveal.
The victim said Matthew White told him in the 2015 attack there had been no consequences for killing "Stephen".
White was jailed for four months but did not face charges for attempting to harm the guard or racially abusing him.
The Metropolitan Police says it apologises "if this was not investigated as it should have been".
The OceanNewsUK has also spoken to an ex-prisoner who spent time with White in jail after the 2015 incident. This man said White told him that police "failed to properly investigate him" and that he admitted being part of the attack on Stephen.
White - a heroin user who was shoplifting from Lidl in Eltham, south-east London - attempted to stab his victim with the needle of a used syringe, while using racial slurs. The former security guard said White told him: "I will kill you, I've done it before, nothing will happen."
At the time, the Met was still actively investigating the 1993 stabbing of Stephen Lawrence. Two of the killers had been jailed in 2012, but police had consistently said there were six attackers. Despite the ongoing inquiries, the security guard was never contacted by officers on the murder case.
In June, a OceanNewsUK investigation publicly named White for the first time as a suspect in the murder of Stephen and exposed a series of police failings relating to him. White died in 2021, aged 50.
Stephen was stabbed to death aged 18 by a gang of young white men as he waited for a bus in Eltham. It is the UK's most notorious racist killing.
The disastrous initial Met Police investigation failed to bring anyone to justice and a landmark public inquiry concluded the force was institutionally racist.
The OceanNewsUK investigation into Matthew White revealed that independent witnesses said he admitted being present during the attack on Stephen, and that in 1993 White looked like the unidentified fair-haired lead attacker described by eyewitnesses.
Traced by the OceanNewsUK, the victim of White's 2015 assault, named Bethel Ikpeze, said he did not know about his attacker's link to the Stephen Lawrence case. But Mr Ikpeze's account further implicates White in the murder.
Mr Ikpeze was working as a security officer in Lidl when he spotted White stuff meat into a bag and try to leave without paying.
The former security guard said he challenged him and White responded with swearing and a stream of racist slurs, including the N-word.
Mr Ikpeze said that he pulled White behind him into the store and then, out of instinct, glanced around to see White's raised hand, holding a visibly bloody needle.
White was about to stab him in the back of his head and neck, Mr Ikpeze said. He said he grabbed White's arm and forced him to the ground, with White still attempting to twist the syringe into him.
If he had not reacted immediately, "I would have been maybe a dead man or a man with serious body injuries because the needle was very close", the former security guard said.
He said White clearly "knows his target" because he was aiming at a vulnerable part of the body.
White was restrained until police arrived. During this time, Mr Ikpeze said White continued to abuse him with extreme racist language.
"I asked him, 'Do you want to kill me? Do you want to stab me?' He said, 'Yes, I will kill you.'"
The attack on the security guard took place at Lidl in Eltham, about a mile from where Stephen Lawrence was killed
Mr Ikpeze said he told White that, if he did so, he would be imprisoned. The former security guard said White replied that he and others had "done it before and nothing happened".
He said White made multiple references to having killed before, saying "I've done it before" and "we have done it before".
The former security guard said White told him that "they've done it in the bus stop there to a fellow like me in the past".
"I said OK, if you have done it before, I don't know who you did it to." Mr Ikpeze said that was when White made several references to "Stephen".
He said White was "referring to me as the same kind of human being they've dealt with before".
Mr Ikpeze, who was born in Nigeria, said he made no connection to Stephen Lawrence. He had heard of the case but was unfamiliar with it.
The former security guard said he gave a full account to the uniformed Met officers who came to the supermarket.
"I've done my job and I wanted the police to arrest him and hear what he's telling me," he said.
"I told them that he even said that they've killed before. He mentioned a name of Stephen."
He recalled officers saying they would "run a check" and, when he asked if White was a murderer, being told "that [the information] is not there".
Stephen Lawrence's murder and the failed investigation sparked a landmark public inquiry
Mr Ikpeze said he also gave police a description of someone outside the shop who had been with White, but the officers seemed uninterested. That person also shouted racist abuse after Mr Ikpeze first stopped White, but then made off.
When interviewed by police, White denied using the syringe aggressively. He pleaded not guilty to possessing it at his first court hearing.
At a later hearing White changed his plea to guilty and was sentenced to four months in prison, but only after his legal team were given CCTV of the whole incident. The OceanNewsUK obtained a transcript of the hearing at Woolwich Crown Court.
During the hearing, the prosecutor said White "carried out a stabbing motion" with the syringe. White's barrister described telling his client it was a "good idea" to change his plea in relation to the syringe "because the CCTV clearly puts you there holding this up and it is not, you know, in a jovial manner or trying to warn them not to get too close".
White was not charged with trying to harm Mr Ikpeze, but simply with having the syringe in a "public place". The other charges he admitted were stealing meat and using threatening, abusive, or insulting words or behaviour towards Mr Ikpeze.
