There was a chilling message included in the black bag of human limbs found by a group of teenagers on the side of a road in a north Dublin housing estate last Monday night.

The message was in the form of a pair of black and white flip-flops. The message was clear to the rival gang criminals for whom it was meant: "Don't think you can beat me up on the street, steal my sports bag and shoes and get away with it."

Gardaí believe the killers were on their way to deposit the remains of Keane Mulready-Woods outside the home of a rival gang member just before 10pm that night when they "got spooked" by the presence of a Garda Armed Support Unit nearby.

It was in the area for a completely unrelated reason but the killers dumped the sports bag and drove away.

Gardaí also believe further human remains that were found in the early hours of Wednesday morning in a burning car in Ballybough in Dublin's north inner city were also originally destined to be left outside the home of another major criminal.

This man, who lives in Co Louth, is suspected of being responsible for many other heinous crimes, including the disappearance and suspected murders of Willie Maughan and Ana Varslavane who have not been seen since April 2015.

However, by late Monday night the remains of 17-year-old Keane Mulready-Woods, from Beachwood Drive in Drogheda, Co Louth, had already been discovered and an intensive murder investigation was under way. It was no longer possible for the killers to continue with Plan A.

Detectives believe Keane Mulready-Woods was killed in a house in Drogheda

Plan B necessitated the rapid disposal of the child's remains. Some were left on the side of the road in Coolock; some were recovered from the burned-out stolen blue Volvo V40 on Wednesday morning, while some of Keane’s remains are still missing. Gardaí therefore cannot definitively say how he died.

The gruesome and brutal murder has been shocking on so many levels. Firstly, it is a gangland murder, but it is also the gangland murder of a child.

Secondly, there is the barbarity of the dismemberment of the teenager's remains and the subsequent dispersal of those remains.

Thirdly, there is the considered and calculated nature of that act in that it was not done to dispose or conceal evidence, to make the crime more difficult to solve - or to ensure the guilty could continue to walk free. It was done to taunt and threaten rival criminals and to send a message that no act is too savage for this criminal gang to contemplate or commit.

Fourthly, there is the unrepentant nature of the suspects involved and the wider gang membership whose leaders have been seen casually going about their business in public after the murder. They have been seen on the streets and drinking in various pubs in Drogheda.

From the criminals' perspective, the act of dismembering the child’s body as a strategy in an ongoing organised crime feud has the additional devastating impact of heaping more pain and suffering on an already grieving family.

The murder is of itself an outrage; the way the victim’s remains were treated is another. The violation of Keane’s body has exposed his parents, brother, sister and other loved ones to an unspeakable indignity, but it also sends a message to the wider community that this criminal gang is brutal, ruthless, invincible and untouchable.

This was the gang’s public message, but the deliberate inclusion by the main suspect of the flip-flops in the bag of limbs discovered in Coolock on Monday night was a private message from one gangster to his rivals that he knew they would fully understand. It relates back to an attack on the main suspect on the street late last year just after he got out of jail.

The attack by a man who believes the suspect in this week's murder also shot dead his father over a decade ago, was filmed and posted on social media.

Gardaí suspect but have not confirmed that 17-year-old Mulready-Woods was also there that day holding the mobile phone and recording the attack.

The criminal was confronted coming out of a gym. His bag with a pair of black and white flip-flops was also stolen by the attackers. The flip-flops were subsequently used in another online image.

A detailed forensic examination of evidence is being conducted at Garda Headquarters

A rival gangster was pictured wearing them, pointing to them and mocking the suspected killer. They laughed at the idea of a hitman wearing flip-flops in the gym. The move was designed to taunt and humiliate him and it is clear that he felt the need to hit back.

The hitman's reply was to leave a pair of similar black and white flip-flops in the sports bag with the remains of Keane Mulready-Woods to be found by his rivals. The gardaí retrieved them as evidence in the murder inquiry.

Social media has been weaponised by both gangs in this dispute. Just as others including members of the Travelling community involved in family feuds and bare-knuckle fighting have recorded threats on tapes and online and posted them to rivals, those on both sides of the Drogheda gangs feud have adapted the same tactic.

As well as fighting, stabbing, shooting and killing each other in Dublin and Louth, the gangsters have taken their feud online. The images and recordings, which are widely available, are disturbing and distressing.

Gardaí have established that images of a torso and human limbs, as well as a video showing a young man being attacked, are not connected to the murder of the teenager. They have asked people not to contribute to the cycle of threats and violence by circulating this material.

They also say they have made significant progress in the investigation. The week-long forensic examination of the house in Rathmullen Park in Drogheda, the suspected murder scene, has yielded significant evidence.

Forensic specialists from the Garda and Forensic Science Ireland have found blood stains in the house, including on the floor boards. They have discovered evidence of attempts to deep clean the house and have seized cleaning products and equipment.

They have seized a number of very large knives and suspect there are blood stains on them. However, this needs to be confirmed by a detailed forensic examination in the laboratories of Forensic Science Ireland at Garda Headquarters.

Search teams have also found other evidence in a shed at back of the house and evidence of a fire in a green area at the back of the property. That material is also being forensically examined to see if it relates to an attempt to destroy evidence. Detectives believe Mulready-Woods was taken to the house, murdered and his body dismembered.

Gardaí have also identified a number of suspects for the murder, in particular two individuals associated with the feuding criminal gangs. One is in his 20s, another in his 30s; one is from the Drogheda area, the other from the Coolock area of north Dublin. Neither of the men live in the house being forensically examined.

The house in Rathmullen Park has been forensically examined

Investigators have also recovered the car they believe was used to move the child's remains around Dublin and Louth after the murder. The 161 D blue Volvo V40 with alloy wheels was stolen in Sandymount in Dublin on 15 December and was fitted with false plates, 141 MO 1925.

Gardaí have received information in relation to at least two sightings of that car but they still need to track its movements up to last Wednesday morning when it was found on fire in a lane in Dublin's north inner city.

It had four alloy wheels when stolen, but when it was found it had only three alloys and the spare wheel on it.

The origins of the Drogheda feud, which has resulted in the murder and mutilation of a teenager, lie in the attempted murder of one gang leader by another. The target was not killed but seriously injured and left with life-changing injuries.

For a man who was proud of his ability and appearance, who had spent thousands on dental work alone, shortly before he was shot and severely disabled, this has been a very difficult cross to bear.

His new life has been made more difficult for him by the continuing taunts and threats to him from rival gangsters, which clearly display the absence of any sense of empathy, decency, morality or remorse.

Shortly after he had shot and injured the man, the gunman phoned him to personally taunt and threaten him while he was still recovering in hospital. The conversation went as follows:

"What's the story?" the gunman said to his victim. "Do you remember me?"

"Never met you in me life," the victim replied.

"Just ringing to say how ya getting on, are you alright?" the gunman asked his victim.

"Oh, I’m alright," the victim replied.

"Just thinking around the last while man, I feel bad for you to tell you the truth, it’s hard on top isn’t it?"

"Ah, it’s hard on the top boy."

"C’mere tell me, listen, how are ya getting on? Alright?"

"Sure, I’m after telling you same question twice," the victim replies, slightly irritated.

"C’mere listen, you still up in the hospital, are you man?" the gunman asks.

"Yea, sure what do you want?"

"Yea, that’s what I’m saying, the next day or two, me and me mates goin' to drop you up a few flowers, yeah?"

"Yea, I love flowers, would you like flowers back son?"

"I do, I do, I do yeah but c’mere yea, are you stuck for anything up there, do you need anything, no?" the gunman taunts.

"Ah, I was never stuck for a thing in me life" the victim replies suspiciously. "I wasn’t a corner boy like you."

And on it goes in the same confrontational, taunting and mutually degrading fashion for another five minutes with sexually explicit references and insults to named family members.

The gunman recorded the conversation and posted it on social media as part of what is clearly an ongoing propaganda war among these two organised crime gangs. Since that conversation took place three people have been shot dead.

The gardaí say the gunman is one of the most dangerous members of the gangs. A relatively young man who’s strong and well built.

The gardaí have found him topless dressed only in shorts, white socks and runners when they have gone to arrest him. He doesn’t come quietly and armed support is always needed.

The man’s attire is in sharp contrast to that of his younger rivals in the other gang, including the late Keane Mulready-Woods, who displayed the trappings of organised crime.

When the 17-year-old disappeared last Sunday at 6pm, he was dressed in over €1,000 worth of designer clothes; a Navy Hugo Boss tracksuit, Black Hugo Boss runners (brown sole, black laces), a Red/Orange Canada Goose Jacket and a Gucci baseball cap. Gardaí are still searching for his clothes.

Gardaí released pictures of the clothes that Keane Mulready-Woods was wearing

The officer leading the murder investigation, Chief Superintendent Christy Mangan, described Mulready-Woods as a child who had his whole life ahead of him, a child who was making his way in life. However, from a very early age Keane was drawn in to the criminal gangs and clearly lost his way in his short life.

As a juvenile he had convictions for minor drugs and road traffic offences, before moving on to serious crime. He was linked to the Drogheda feuding gangs and a major Dublin criminal who is based on the northside of Dublin and nicknamed 'Mr Big'.

Keane was involved in drugs, violence, intimidation and arson attacks and last December was convicted of threatening and terrorising a family in Co Louth.

A week before he went missing he was officially warned by gardaí that his life was in danger.

Mediation attempts over the past two years have failed to resolve the feud in Drogheda. The gangs have refused to listen to, let alone engage with senior church leaders, the gardaí, politicians, voluntary organisations or community leaders.

The feud is personal. It is rooted in a vendetta. Both sides have been poisoned with vengeance.

While vengeance is driving this murderous feud, there is no doubt that it is being fuelled by an insatiable desire for drugs, particularly among young, educated, wealthy professionals.

Gardaí found further human remains in a burning car in Ballybough in Dublin

This weekend will see queues of young people in pubs and nightclubs waiting to get in to the toilet stalls to snort copious amounts of cocaine.

This drugs economy, the criminal networks who supply them and the people who take them have all - in the words of the officer leading the murder investigation - "contributed to Keane’s death".

"Just look at the fall out from you buying drugs," Chief Superintendent Christy Mangan said. "It's damaging our children and our society."

The murder of Mulready-Woods is the latest act of barbarism between the two gangs, but no one with any knowledge of this feud believes it will be the last.

Gardaí fear that each side will continue to seek to outdo the other with acts that display a greater level of depravity and callousness.

The gardaí say they are assiduously working to prevent this taking place. Chief Superintendent Mangan has stressed their primary concern is the preservation of life. Their primary responsibility is to the community and its safety.

The reality of this feud is however, as is the case in so many aspects of organised crime worldwide, that it can only end for the participants in one of two ways; the jail or the grave.

The Drogheda Feuding Gangs - Who's who?

There are two family based criminal gangs - rooted in Drogheda and County Louth - with allies and associates from Coolock and north Dublin.

Family Gang One:

Drogheda members:

The first victim of this ongoing feud who was shot and seriously injured - left with life-changing injuries.

A major criminal based in Gormanston, recently released from prison, suspected of involvement in the disappearance of Willie Maughan and Ana Varsalane.

Keane Mulready-Woods - 17-year-old murdered and dismembered.

Coolock members:

Son of a man who was shot dead over a decade ago seeking vengeance for his father’s murder.

Kenneth Finn - shot dead in Coolock last year - suspected to be the gunman who shot dead leader of the Real IRA Alan Ryan in 2012.

Mr Big - Major Dublin criminal from northside of Dublin.

Family Gang Two

Drogheda members:

Two brothers

A man in his early 20s, suspect for the murder of Keane Mulready-Woods and main suspect for shooting the other main gang figure in the attack, which left that man with life-changing injuries and started this feud.

Coolock members: