Some are small-time gangsters who have watched too many movies, or look up to the criminal figures in Ireland and decide they want to show their mettle. Instead, they are in prison for a very long time.
There was little sense in Jimmy Lammon cycling up to Jason Doogue (22) in Athy in 2015 and shooting him three times.
The pair had exchanged words earlier, which was enough for the then 48-year-old Lammon, who had connections to a Carlow gang, to get a handgun and make good on threats he had made.
Just two years earlier another wannabe gangster in the same Co. Kildare town, Darren Wynne, booked himself a life sentence when he shot Jamie Lyndsay in the head with a sawn-off shotgun.
Wynne claimed he was being harassed over a €1,000 debt and tried to cover up his guilt by posting sympathy messages on social media following the shooting.
Likewise, Trevor McCabe resorted to lethal force in Ballyconnell, Co Cavan, in 2008 when he shot Darren McGrath as he slept in bed.
The dead man had just been released from Loughan House and had served time for drugs trafficking offences.
Being a small-time crook who acts the big man doesn't mean less time will be spent in prison, as shown by Martin 'Mollie' O'Leary who is now 20 years behind bars for killing a man in Cork 2002.
Even when money changes hands, there is no guarantee a killer will do a "professional" job.
For years mystery surrounded the 2005 killing of Irene White at her Co. Louth home.
There was a breakthrough in the case when Anthony Lambe told a girlfriend he had carried out the murder for which he got €2,000.
He had been struggled with debt, was using drugs and had been promised €25,000 for the contract killing.
Lambe had been recruited by Niall Power who then confessed his role and was also jailed for life in 2019, although the 'mastermind' behind the murder plot has yet to face justice.
Another "amateur" behind bars is Paul Hopkins who was hired by Jacqui Noble to kill her abusive partner Derek Benson in May 2000.
Hopkins, who used a sword in the gruesome slaying, left such a mess he attempted to set fire to the scene, the Gardaí were soon alerted to the body in a Ballymun flat.
Hopkins is nearing release at Loughan House open prison while Ms Noble has been free on licence for a number of years.
There was also a lack of planning when biker Alan 'Cookie' McNamara killed Andrew O'Donoghue a member of a rival club in June 2015 as others were in the middle of pursuit.
Since the killing, McNamara's motorcycle club has become a chapter of the Bandidos.
Graham McEvoy, known as a drug dealer, was also keen as an 18-year-old to make his mark when he stabbed and killed Paul Curran (23) at a Crumlin flat complex in revenge for an attack on him.
Daniel McDonnell was much the same age in 2012 when his attempt to intimidate a rival with a shotgun blast ended up in the murder of 16-year-old Melanie McCarthy in Tallaght.
The same sense of arrogance led brothers Jason and Dean Bradley, then aged 19 and 23, to carry out the brutal revenge attack on Neil Reilly after chasing him across Dublin to stab and run over him.
Reilly had fired shots at the family home in a doomed bid to get Jason to pay back a €9,000 drug debt.
Two Polish gangsters also thought little of the consequences when they grabbed a man off the street in front of witnesses in Athlone in 2014.
Cage-fighter Leszek Sychulec and Andrzej Gruchacz beat Patryk Krupa senseless and left him to drown in the Shannon river.
Another big-fish in a small gangland pond was Maurice Power, who in 2012 blasted his old pal Shane Rossiter with a shotgun outside a house in Clonmel, Co. Tipperary. A festering feud in the town had led Power to kill the 30-year after a house party.
Stephen 'Ned' Kelly in Ballymun took the same step when he opted to shoot Ian McConnell outside his home in 2005. A feud between rival gangs had led to tensions, prompting the murder in front of witnesses.
There was no real explanation put forward during the trial of Declan Sheridan and James O'Connor as to why they killed a French busker living in Bray, Co. Wicklow in May 2009.
Shots were fired through the window of musician Charles Sinapayen's apartment and he died two days later from his injuries.
In the same county in August 2009, Stephen O'Meara was shot and buried in a shallow grave where his remains were not found for three months.