Mark Sam Arthur

‘I’m not saying it was right for me to take another person’s life. But sometimes it has to happen.’

- Mark Sam Arthur

There’s no argument about who killed Esequiel Fonseca Sr. on December the 21st, 1996. It was Mark Sam Arthur. The police know it, the courts know it, Mark knows it. Esequiel even knew it in the split second between the bullets going into his head and death.

The question is ‘why?’

Does it really matter why? Murder is murder, after all. Killing another human being is morally wrong. It’s one of the worst crimes a person is capable of committing. It’s a sin. Motive is still important, though. It’s important to help us understand context and get a better understanding of what happened in any serious crime. It’s also important to the legal system so they can respond accordingly with an appropriate sentence.

So why did Mark Arthur empty an entire clip into the brain of Esequiel Fonseca Sr.? The answer is out there. The only trouble is… so are a Hell of a lot of lies.

There are several possible motives for the murder. First, though, let’s quickly run down what happened…

It was five days before Christmas ‘96 in Houston, Texas. 17-year-old Mark Arthur and his 16-year-old friend Mason Hughes stole a blue Cadillac at gunpoint from an elderly man outside a convenience store. The next evening, with Hughes driving and Arthur in the passenger seat, they tracked Esequiel ‘Big Zeke’ Fonseca as he left work. The two teenagers in the stolen car pulled up alongside Fonseca’s vehicle. Arthur wound down the passenger side window, cocked the 9mm and unloaded it into the driver of the white Lincoln next to them. 

13 bullets were fired. Seven entered Big Zeke’s head, arms and torso.

The two teens then sped away. They were both arrested just a few days later.

Back to that pesky ‘why?’ question.

The crime was premeditated. It was cold-blooded. It was every bit the capital murder. But what was the reasoning behind it? There was no robbery element. It was a targeted attack too, so it was no random thrill kill. And, while the boys had gang ties, this was no initiation hit. So what was the motive for Mr Fonseca’s murder? 

Let’s explore the possibilities. At one point or another, the following motives have been suggested by those involved in the case. The truth is somewhere here:

‘I couldn’t just sit there and watch some guy beat up on a woman. It’s not gonna happen.’

Mark Arthur

●    Possible motive #1: Let’s start with that quote. According to the man himself, Arthur saw and experienced physical abuse as a child. He abhors violence against women and the vulnerable. Fonseca was married to his friend’s mother and used to beat her. Disgusted, saddened, angry and determined not to have the beating repeated, he shot and killed Fonseca.

●    Possible motive #2: Furious about the spousal violence, Mark Arthur jumped Fonseca and beat him up. Later, the victim would threaten to murder Arthur as an act of revenge. Afraid for his life, Arthur shot and killed Fonseca as a pre-emptive strike. 

●    Possible motive #3: Mark Arthur was having an affair with Carmen Fonseca, Esequiel’s wife. She was eight months pregnant with his child. One day Esequiel beat her so badly she lost the baby. Disgusted, saddened and angry, he shot and killed Fonseca.

●    Possible motive #4: Arthur was having an affair with Carmen Fonseca. He wanted to get rid of his love rival and replace him. Jealous and seeing no other way to get rid of the man, he shot and killed Fonseca.

●    Possible motive #5: There was a sizeable life insurance policy (some $220,000) taken out not long before the murder. Carmen wanted to kill her husband and cash in on it. To do so, she needed a gunman. So she seduced Mark Arthur and convinced him to do the deed, in return for a cut. Desperate to please Carmen and make some money, Arthur shot and killed Fonseca.

The truth is most likely a muddied mixture of some or all of these theories. 

Arthur had been physically abused by his stepfather as a child and seen his sister beaten by her partner. He does have a pathological hatred of men who beat women and children.

There was some kind of relationship between Mark and Carmen, they've each admitted to it at various times. Mark Arthur now claims that their affair was brief and only a physical thing. He claims his motive was partly due to his hatred of violence against women, but mostly a ‘kill or be killed’ thing. He feared ‘Big Zeke’s vengeance after the beating he handed him.

Houston PD believes the pair were in it together. The insurance policy is pretty damning when considering this particular theory. It certainly seems to indicate that Carmen was involved. Then again, recorded calls from Mark in custody to Carmen - designed to implicate her - proved fruitless. 

The truth, as it can so often be in such complicated and serious matters, is elusive.

Both Mark and Carmen would be found guilty of capital murder and receive life in prison (although Mark was originally given a death sentence, it was commuted in 2005).

Regardless of the exact nature of their bond or attachment, Mark and Carmen’s lives are indefinitely linked. Mark killed Carmen’s husband, after all. The pair are connected by time and dates as well. Mrs Fonseca was arrested on the exact same date that young Mr Arthur was sentenced to death. And neither will be eligible for parole until at least 2037.

Find out more about the murder of Esequiel Fonseca Sr. when Mark Sam Arthur tells the cameras ‘I am a killer’ in the tenth and final part of the second brilliant series of I Am a Killer.