Father-of-two Richard Deakin was killed with a gun as he lay in his bed at his Staffordshire home six years ago this week.
His mother Carol today made a heartfelt plea for someone to 'tell the truth and end this hell for me and my family'.
Richard, who would be 33 today, was murdered by hired gunman David Harrison, who escaped with getaway driver Darryl Dickens.
Sentencing Harrison, Justice Roderick Evans said 'you were paid by people who are still at large' – but two years on no-one has yet been caught.
Staffordshire Police say there are 'no active lines of inquiry' but the case will never be 'fully closed'.
Speaking yesterday after taking flowers to her son's grave at Willenhall Lawn Cemetery, Carol said: "They say time is a great healer, but I tell you it's not – I will not rest until the person who ordered my son's killing is convicted.
"Justice will never, ever be done until that person is caught and charged.
"All it needs is someone who knows of someone to open up, tell the truth and end this hell for me and my family.
"I can't stand the thought of dying without knowing I have justice for my son."
Carol says she relives the day her son was killed every day.
It was a sunny Monday, and the weekend before she had looked after his children Jessica and Elle, now aged seven and 11, while he took partner Megan to Hoar Cross Hall in Staffordshire.
While there, Richard proposed to Megan with a ring he had bought from the Jewellery Quarter in Birmingham. They planned to marry in the Dominican Republic in the September.
On the way back to their Chasetown home on the Sunday evening, he called Carol, asking her to take the children to his home for when they returned.
However, Carol lost her son's keys and instead Richard and Megan collected the children from her house, 10 minutes drive away in Cheslyn Hay.
"Richard was happier that day than I had seen him for a long, long time," Carol said.
"He was a very bubbly lad. His last words as he left were 'I love you mum', and then he went, calling me later when he got home to say he'll see me soon." The following morning, Carol went to work for Birmingham City Football Club, preparing for a morning conference.
Meanwhile, at Richard's home in Meadway Street, just before he was shot dead at around 8.30am, he said goodbye to his two daughters before Megan went on the school run.
Carol said: "I remember sitting down at my desk, I had a bowl of cereal in my hand and the phone rang – it was Megan.
"She rang me and said 'he has gone, he is no longer with us.'
"I dropped the cereal bowl and it broke. I was hysterical, I was screaming down the office, it was absolute bedlam.
"Security had to carry me down the stairs and I was driven to Burntwood Police Station – I kept asking 'who would do this to my son?'"
At about 1pm, Carol returned home where family members and friends visited throughout the evening to pay their respects. Carol added: "I think about him every day. All the time. When I go to bed at night he is the last think I think of, then in the morning I see him once more."
"I live the nightmare he lived, I can't express how I feel know my son was lying in his bed in his house when someone with a gun cam into his bedroom and gunned him down."
A murder investigation was launched after the fatal shooting and there followed a BBC Crimewatch appeal.
Harrison, then aged 63, was arrested, charged and sentenced to 37 years in jail for murder in December 2012.
Dickens, who was 34, was also convicted of murder and sentenced to a minimum of 30 years at the same trial.
Tipton drug lord John Anslow was initially arrested by police investigating the case but he was acquitted of any involvement after a trial at Woolwich Crown Court in 2014.
Anslow is currently serving a 29-year prison sentence after being given 22 years for conspiracy to supply cocaine and cannabis in 2012.
In 2014, Anslow pleaded guilty to conspiring to escape from prison – an act which sparked a worldwide manhunt – and was handed a seven-year sentence.
Detective Chief Inspector Darren Harding, of Staffordshire Police, said: " In cases where some, but not all, suspected offenders have been convicted, Staffordshire Police conducts periodic reviews to ascertain if there is any new evidence available.
"Consequently, cases of this nature are never fully 'closed', even if there are no current active lines of inquiry."
Anyone with information should call 101, or Crimestoppers on 0800 555111.