The video shows Forde stood at the victim's front door at 9:30 AM, wearing a high-vis vest and holding an Amazon box, where he knocked and waited patiently.
But upon hearing the door open, he quickly discards the empty box and pulls a fully-loaded shotgun from underneath his coat.
The victim, who was at home with his daughter and on the phone at the time, reacts quickly and immediately dives on the gun, as a desperate struggle spills out into the front yard.
Warning: Graphic Content
Holding on to the shotgun with both hands for dear life, he falls to the ground as the assailant rains down punches and kicks, but the homeowner refuses to let go.
The victim later told police Forde roared at him to let go of the gun or he would be stabbed; but still he refuses. He finally manages to prise the gun from Forde's hands, before throwing it under a nearby truck.
Meanwhile, the victim's screams for help attracted a number of passers-by, as well as some nearby construction workers, who rushed to the scene and restrained Forde before he could retrieve the weapon or escape.
Police soon followed, and Forde was arrested. They retrieved the shotgun from the scene, which was found to be viable and loaded with two live cartridges.
The victim was taken to hospital, where he was treated for bruising and a broken nose.
Forde pled guilty to possession of a firearm with intent to cause fear of violence, possession of a prohibited weapon, and possession of a firearm by a person prohibited. He is due to be sentenced on July 29.
"The victim had no idea what was about to unfold when he saw what he thought was a delivery man bringing a parcel to his address," Detective Constable Imran Hansraj of the Specialist Crime Command said in a statement. "He had been home with his young daughter and was going about his business as usual when he was thrust into an incredibly frightening ordeal in which he fought for his life."
"His life was turned upside down in a split second by Forde's actions, which were wicked and cowardly in the extreme. He was disguised and armed with a lethal weapon but the victim displayed [incredible] bravery to disarm him. He was lucky that a number of members of the public took heed of his cries for help and came to his aid. They too deserve enormous recognition."
"I hope Forde will now spend a substantial amount of [time in] prison, and I am sure that London will be all the safer for it."
In an unrelated incident which occurred just six days after this one, New Jersey federal judge Esther Salas's son was shot dead and her husband wounded on their own doorstep, by a disgruntled lawyer posing as a FedEx worker.