Yvonne Black's 52-year-old husband, the father of their two children, was travelling to work at Maghaberry Prison when he was ambushed and shot near Lurgan, on Thursday 1 November.
"It was just a normal Thursday morning ..." Yvonne told UTV's Jane Loughrey, in her only interview about the tragedy, describing how David had been up early to defrost her car windscreen for her before heading to work himself.
She had no idea what lay ahead.
While threats had been part and parcel of being a prison officer in the past, it wasn't something that had particularly concerned her husband or their family in recent years.
It was while working on the wards at Altnagelvin Hospital in Londonderry, where she's based as a Macmillan nurse, that Yvonne was paged to take a call from her son Kyle.
The 21-year-old sounded worried and asked if she had heard from his dad that day. She hadn't since they'd spoken briefly on the phone early in the morning.
"He went really quiet and I said: 'Kyle, what's wrong?' And he said: 'Mummy, I'm really worried. I've heard something ... I've heard there's been a prison officer shot on the motorway.'" Yvonne recalled.
"At that precise minute, I could honestly say in my heart I didn't for a minute think it was David."
I said to Kyle: 'Don't worry - this is not your daddy. This is awful, but this is not your daddy.'
Kyle had been trying to call his father and there had been no response, but Yvonne tried to reassure her son that many other prison officers travelled on the motorway every day.
"He said: 'But Mummy ...' And when I heard that, I knew there was something else," she said.
Kyle explained that he'd already called his sister, 17-year-old Kyra, who was at home as she was off school for the Halloween holidays.
She'd told him that she'd missed answering the door when the bell rang, but that she had made it downstairs in time to see a police car pulling out of the drive.
For Yvonne, that changed everything.
Telling her son she would ring the prison, speak to his dad and call him straight back, she ran from the hospital ward to her office where she found one of her colleagues to make the call for her.
"I sat with my head in my hands as she was having the conversation," she said.
But, having looked up as her colleague found a pen and wrote down a number, Yvonne also saw her write the word 'governor' beneath it.
"I just started to cry," she said.
It was at that moment that the office door opened and another colleague showed a policeman and a policewoman into the room - finally breaking the news that would shatter the Black family.
Flanked by two of her colleagues, Yvonne was led through the hospital and out to a waiting police car which would take her home to Cookstown.
"Part of me wanted to get home and the other part of me wanted to run away ... That journey home from Altnagelvin was the longest journey in my life," she said.
"I just wanted to hug the children."
Arrangements were made for Yvonne's brother to go to be with Kyra, while friends went to get Kyle.
But, for Yvonne, the scene back home - with police cars everywhere - would only bring back the painful, still raw memories of her father's death in a farming accident only a year earlier.
From then until the day of David's funeral, life held an unreal quality for the family as they struggled to cope with David's loss and the violent way he'd been taken from them.
He was the love of my life ... a brilliant husband and father ... and I never got the chance to say goodbye.
In the hours before laying their husband and father to rest, something changed though.
"For some reason, that morning, I can remember just getting ... a peace or a strength from somewhere," Yvonne said.
"I remember saying to the children: 'We have cried for five days behind these doors. We have to go out and hold our heads up high.'"
She added: "For all these years, we couldn't tell anybody David was a prison officer and, for the first time in our lives, we could go out and it didn't matter."
Kyle and Kyra were particularly determined to pay tribute to their dad, having been devastated by his loss in such terrible circumstances.
"I couldn't believe this could happen to anybody, never mind Daddy," Kyle told UTV.
While finding the strength to speak at his funeral was hard, Kyra managed to recite a poem she had written specially for her father.
"I was just so proud of him and I just wanted everybody to know ... how amazing my daddy was," she said tearfully.
According to Yvonne, David was proud to be a prison officer and part of the justice system - he held his colleagues in high esteem and tried to do his best for the prisoners he guarded.
While his wife knew that would be the case because of the man he was, she was given proof in the days and weeks after his death.
"I've had so many cards and letters from prisoners, ex-prisoners and serving prisoners, saying this shouldn't have happened," she said, adding that she was humbled by the level of support.
"I got a letter from a lady whose son is in serving at the minute. She said that he rang her on the Thursday night, so upset on the phone that this had happened to David ...
"It makes me realise that he did make a difference in their lives."
They can take Daddy from us ... but there's a lot of special memories that we'll always have and keep in our hearts. They can never, ever take that from us.
A group calling themselves 'the IRA' admitted carrying out the murder, but David's family want only justice - not revenge.
"David worked as part of the justice system - he lived for it, he worked for it and unfortunately he died as part of that justice system," Yvonne said.
"So, as his wife and as his family, we have to believe that justice system will do right by David and catch these people."
Fighting back tears, she pleaded for anyone with information to come forward - as one tiny detail could be "the piece of the jigsaw that makes everything else fall into place".
She added: "It won't bring him back, but least I'll know that justice has been done."
The Black family and police are urging anyone with information about David's murder to contact the PSNI on 0845 600 8000, or Crimestoppers anonymously on 0800 555 111.