Jastine Valdez murder: Nothing is completely random

In a killing like this, there is usually a psychological build-up, a pathway to violence that progresses to a fantasy about a plan to kill, writes Sinéad McDonough

Jastine Valdez murder: Nothing is completely random

In a killing like this, there is usually a psychological build-up, a pathway to violence that progresses to a fantasy about a plan to kill, writes Sinéad McDonough

As a lecturer in forensic psychology, I often lecture on the topic: Why do people kill? Why does someone commit murder? How can we explain acts of violence?

It is very difficult to answer these questions because every killer and every killing is distinctive. While it is helpful to try and isolate one specific factor that can account for the act of killing, the diversity of actions subsumed under the heading of “illegal acts” means that a unitary causative factor cannot easily be identified as an explanation for killing.

It is of paramount importance that we try to recognise and understand the muti-causal nature of killing. Personality variables, genetic predisposition, mental illness, and even the home environment may all combine to the point where a criminal pathway may be more likely. Nevertheless, most of society seems to have their pet theories as to why others do bad things inclusive of killing. Pet theories, however, can be dangerous, as it may cause loss of objectivity because of one’s “devotion” towards the pet theory.

While there are several different types of killers and offenders, the most basic typology and the most widely used by investigators is the organised/disorganised dichotomy attributed to FBI profilers. This typology is often used by forensic psychologists to understand the motivations and characteristics of a serial killer. The HT (Holmes Typology) classifies killers into two distinct groups.

The organised killer is usually an individual who lives a seemingly stable, normal life. This individual is usually gainfully employed, highly intelligent, and very often has families and good friendships and will often plan their crimes even for years in advance.

The disorganised killer tends to have a more spontaneous lifestyle. Below-average intelligence is a characteristic. Their victims are random and do not tend to fit a certain demographic. This killer will usually leave evidence at the crime scene and the murder weapon. Crime scene locations are often in close proximity to the killer and killings take place at the location where the victim is found, hence the evidence left behind at a crime scene.

While these typologies help us to understand the mind of a serial killer, it is far more difficult to understand the motives behind a single, isolated killing.

A person’s sudden leap to killing always comes as a shock. This certainly was the case when Mark Hennessy ended the life of Jastine Valdez.

While there is no immediate indication as to why Hennessy chose to kill Ms Valdez, a woman apparently unknown to him, the decision of a married father to commit what appears to be a first, random killing at this stage of his life does seem unusual. Trying to get an understanding of this unexpected and random act of killing is uncompressible.

All that has been to date established is that Hennessy was known to gardaí but was not deemed to be a serious criminal. It is known that he was on bail at the time of the murder, having been charged with drink-driving, and was in the past convicted for abusive behaviour in public and for possession of cannabis.

As well as giving an indication as to where the missing woman’s body was — Puck’s Castle — a note written by Hennessy and found in his car is believed to have left a note saying “sorry”. It is unclear whether he was apologising to his victim or to the family he left behind. Despite having a wife and two young children, it seems clear that he did not intend to ever return home. There are also reports to suggest he had gone drinking after the killing. This is indicative of a gross lack of empathy and understanding of the gravity and nature of his crime.

In cases such as this, there is usually a psychological build-up to this point. There is a pathway to violence that generally begins with some thinking and a progression to fantasing about a plan to kill.

The fantasy of killing may then develop to intention, leading a person to track victims and obtain weapons. Research highlights that a person who has already decided to kill may develop a “weird composure”, firmly believing that the moment to turn back has passed.

This may have been the case for Hennessy, who called his family to say “I’m not coming back” and also failed to attend his nephew’s communion over the weekend.

Mark Hennessy
Mark Hennessy

Tragedies such as this are rare in Ireland and hence it is very difficult to compile a comprehensive profile of this killer. A profile of this nature is also difficult to collate, given that the offender in question was a middle aged man who suddenly turned to randomly killing a beautiful young woman. While it appears that there had been no prior links between Hennessy and Ms Valdez, there is a possibility that the 24-year-old student may have been watched by her killer. This is one of the most pressing issues to try and determine here.

Research on stalking points to the fact that when a stalker’s yearning is thwarted, the danger escalates. Oftentimes, as grandiose fantasies collapse around the stalker, they grasp at the only tool that can boost their self-worth: Anger.

With reference to the research in this area, there are clear risk factors to snapping. These include seizures, alcohol and drug abuse, and psychosis. Certain life experiences can also be a contributing factor to snapping. Damage to the brain’s temporal lobe, which contains structures involved in fear response, has also been suggested to have a connection to violence.

The uncertainty and lack of answers in random acts of killing is what makes these types of crimes so difficult to understand, both for the families and for the general public. These tragic cases undoubtedly catch our attention and prompts questions around public safety. It is very difficult to try and determine the motives for Hennessy’s actions. The problem with seemingly random acts is that motivations are completely unknown, and there can be several factors at play.

Without a connective motive, we may never fully understand why Mark Hennessy took the life of Jastine Valdez. Nothing, though, is completely random. I don’t believe there is such a thing. Random implies that there is no thought. But there are always motivations for taking the life of an innocent person.

- Sinéad McDonough has a PhD in forensic psychology

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