Mr Powell, 39, was discovered in Higham Station Avenue, E4 on Monday 5 July after being shot a number of times by a lone gunman.
Enquiries by officers continue and the investigation team is using the three month anniversary of Mr Powell’s death as an opportunity to encourage people to come forward with fresh information about the incident.
Detectives will be in the vicinity of Higham Station Avenue on Monday 4 October between 22:00hrs and midnight conducting inquiries, handing out leaflets and speaking to members of the public.
Mr Powell’s partner, Anne Boriel – who is eight months pregnant with their child – has spoken of her anguish at losing her fiancé. She said: "Wayne was a fiancé, a father, a son, a brother, an uncle and a friend, and he was tragically stolen from us. There are not enough words that could express the pain, anguish, grief and sorrow that we as a family are going through.
"Wayne was a kind, loving, good-natured man who from the age of 16 entered the world of work and became the hard working man that I met 12 years ago. He did not deserve to be taken away like this. He loved and cherished his family and leaves behind five children as well as his unborn son who will never know his daddy.
"He had so much to live for and now someone has robbed me and my children of a future. All I can do now is pray and ask for God’s strength through this difficult time.
"Please if anyone knows anything do the right thing and go to the police. No one deserves to be taken like this. Imagine it was your son, your husband, your brother, find it in your hearts to come forward and not be afraid and bring this perpetrator to justice."
Police were called at 23:14hrs on Monday 5 July regarding a man collapsed in Higham Station Avenue, E4.
Wayne Powell, of Stonebridge Road, N17, was discovered suffering multiple gunshot wounds. He was taken by ambulance to RoyalLondonHospital where he was pronounced dead.
A post-mortem examination gave cause of death as gunshot wounds.
It is believed Mr Powell was in his car when a lone gunman approached the vehicle. Mr Powell got out of the black BMW and started to run away. The suspect fired shots at him before making off.
An incident room opened under Detective Chief Inspector John Crossley, Trident. He said: "We are looking for a lone gunman who was wearing dark clothing.
"The suspect is believed to have left the scene of the shooting along a footpath in the direction of ConingsbyGardens, and I would implore anyone who believes that they have information that could help this investigation to speak to police."
Anyone who can assist should contact the incident room on 020 8733 4704; if you wish to remain anonymous call Crimestoppers on 0800 555 111.
On 12 July a man [A – 29 ys] was arrested in connection with the inquiry and was taken to a north London police station. He was later bailed to return on a date in October pending