Pamela Humphrey, Oliver’s mother, has also pleaded for information about the person or people responsible for killing her son.

Brent & Kilburn Times: Detectives still believe Mr Tetlow was killed in a case of mistaken identity. (Photo: Met Police)Detectives still believe Mr Tetlow was killed in a case of mistaken identity. (Photo: Met Police) (Image: Archant)

In addition to the renewed appeal, Crimestoppers have also offered a reward of £10,000 for information leading to the arrest and successful conviction of those responsible.

Ms Humphrey said: “March 9, 2017, is one year to the day that my son Oliver Tetlow was cruelly murdered in cold blood - shot dead in a senseless and tragic case of mistaken identity.

“We are appealing again for you to come forward if you know anything, saw anything or can help in any way with the ongoing investigation.

“This appeal is not only for us, but for your family, your friends, innocent bystanders who could be murdered like Oliver was. We are searching for justice, to feel safe in the knowledge that whoever killed Oliver will be taken off our streets.

“We have lived through a terrible year of grief and sadness, having a talented young man with so much to look forward to in life torn from us.

“Every day I miss my son, my family miss him, Oliver’s friends miss him, every day we think of him, every day we all grieve for him. Our pain goes on.

“Despite all the efforts by the police, CPS and courts, so far no convictions have been made.

“We continue to pray that justice will be done and although it will never lessen the loss we feel, it will bring some small comfort to relieve our suffering, our pain, our grieving.

“Please, please help us. Some witnesses have already come forward and we admire them all for their courage.

“Those who haven’t felt able to come forward before, please help yourself; release yourself from the terrible burden you carry.

“Thank you for any information or help you can give, no matter how small you may think it is. The more people who give information, it helps to build a bigger picture to bring about justice not only for us, but for our community.

“With love and hope in our hearts, in memory of our forever loved and always remembered Oliver.”

Police were called shortly before 10pm last March 9 to reports of a shooting in Church Road at the junction with Conley Road.

Accompanied by armed officers and the London Ambulance Service (LAS), they found 27-year-old Mr Tetlow with gunshot injuries. Despite the best efforts of the paramedics he was pronounced dead at the scene.

A post-mortem examination held on two days later at Northwick Park Hospital Mortuary confirmed the cause of death as gunshot wounds.

In the year since Oliver’s murder, detectives from the Homicide and Major Crime Command have followed up on numerous enquires, have spoken to in excess of 100 witnesses and have trawled through hours of CCTV footage.

A significant amount of information has been obtained and passed to officers but police say they have yet to receive the vital piece of information that would finally put the killer or killers behind bars.

Detective Chief Inspector Mark Lawson, from the Homicide and Major Crime Command, said: “The brutal killing of Oliver last March has left his mother and wider family completely devastated and their grief has been compounded by the fact that even after a year they are no closer to getting the answers they so desperately seek.

“Oliver had simply been going about his business on the night of his murder when he was targeted and gunned down in what we still believe was a case of mistaken identity.

“A young man has tragically lost his life and it is only right that we remain resolute in our efforts to convict those responsible.

“This is the first anniversary of Oliver’s death and I am keen to hear from anyone who has any information or who was at the scene of the incident. You may not have come forward at the time of the murder, now is the time to do so, please do not remain silent.

“A year is a long time to go without answers and I would ask that you to take a moment and think about the devastation that has been caused to Oliver’s family.

“I am also directly appealing to the friends and family shielding those responsible. Now is not the time to stay silent.

“If you have the slightest indication that those you know were involved in the murder I would encourage you to get them to hand themselves into the police.

“Oliver’s mother made an appeal for information in the days after her son’s murder and she is bravely doing so again. As she continues to grieve the loss of her son please do not let this latest plea for information be in vain.”

Detectives investigating the murder believe that Oliver was shot by a male who got out of a dark coloured vehicle. After the shooting, the vehicle travelled south along Church Street, towards Harlesden town centre.

Detectives are confident that Oliver was shot by someone firing from an automatic weapon, although they are unable to confirm the exact type. Neither the vehicle nor the weapon has been recovered.

DCI Lawson continued: “In the days after the murder the firearm used to kill Oliver would have no doubt been passed on to someone to hide or to keep safe and there is a possibility that this gun has exchanged hands since.

“It is of paramount importance first and foremost that this weapon is taken off the streets and secondly I would like to appeal to anyone who knows who the gun was handed to or knows where it is now to come forward and speak to us.

“We are pursuing a line of inquiry with another police force as to where the gun came from and to its current whereabouts but it is vital that if you hold any information no matter how small, you do come and speak with us.”

A number of people were arrested in connection with murder with four eventually charged with murder.

Those four stood trial in December 2016 and were acquitted of the offence in early January.

Despite this, the investigation continues with a reward now on offer and with the passage of time that has passed, detectives are hoping that they will finally get the answers they require.

DCI Lawson said: “This is very much still a live investigation, and despite the recent acquittal of the four men we continue to explore new lines of inquiry.

“Allegiances can change rapidly in a year and I am very keen to hear from anyone who for whatever reason didn’t speak to us at the time of the murder.”

Anyone who witnessed the incident or has any information is asked to contact the incident room on 020 8358 0200 or via Twitter @MetCC

Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.