Mary Louise Day: What Happened to Her? How Did She Die?

If there’s one thing absolutely nobody can deny, it’s that the case of Mary Louise Day is as baffling as it is convoluted considering the clashing claims of disappearance, murder, and runaway involved. This much has actually even been evidenced in CBS’ appropriately titled ’48 Hours’ episode ‘What Ever Happened to Mary Day?,’ chronicling everything she allegedly endured right until 2017. So now, if you simply wish to learn more about the same — with a specific focus on her background, her experiences, as well as her ultimate, unexpected fate — we’ve got the necessary details for you.

What Happened to Mary Louise Day?

Although born on February 19, 1968, in wondrous Little Falls, New York, to Charlotte Pressler and Charles Day as the eldest of their three daughters, Mary’s early years were sadly not safe or comfortable. The truth is her parents divorced while she was still pretty young, at the time of which she as well as her sisters were in and out of foster care because their mother just couldn’t provide for them. The latter did tie the knot with William House a short while later, but it wasn’t until he enlisted in the army in 1975 that she managed to attain full, permanent custody of two out of her three girls.

Mary’s youngest sister, Sherrie, had actually already been adopted, so only she and her middle sister, Kathy, returned to Charlotte while she was undertaking her new role as an active soldier’s wife. Though little did anyone know things would soon go from bad to worse as the stepfather allegedly began physically abusing the eldest — it was so bad even child protective service had to be called. But alas, she was eventually turned back over to the family in Fort Ord, Monterey Bay, California, just for her to suddenly vanish off of this Earth in 1981 with no one ready to report her missing.

It was Sherrie who finally contacted local police in 1992 as an adult before candidly discussing the matter again with officials in 2002, resulting in a formal line of deep investigation being opened. This was when it came to light that Mary had ostensibly frequently tried to run away from her Seaside family home following her return from CPS care, yet she was always found by patrolling deputies. Charlotte hence admittedly expected the same to happen this time around too, but July 15, 1981, proved to be the last time she’d see her 13-year-old — then, as time passed, it became difficult to dial 911.

It’s actually imperative to note that the claim of Mary being a habitual runaway could never be verified, yet there is another reason her family might have hesitated to report the little teen missing. Because Charles Day had died in an accident a short while prior, all of his daughters were granted monthly support payments, which her mother was cashing out using her social security number. Nevertheless, what’s stranger is that their neighbors at the time don’t even clearly remember Mary’s existence, plus she had not been enrolled in any school since her time in child protective care.

Then came Kathy’s account of what could’ve possibly happened to Mary more than two decades ago, painting a much darker picture owing to the abuse it detailed at the hands of their stepfather. As per her narrative, told to detectives for the first time in 2002, she as well as her sister had stayed home on that fateful day while Charlotte, William, and their two biological kids went out for dinner. Unfortunately, their dog fell so sick at some point during this that he appeared to be dying, only for the soldier to immediately assume Mary had poisoned him without any evidence upon coming back.

Thus came a hell of a beating, Kathy said, at the end of which she saw her sister with blood coming out of her mouth — the next morning, Mary wasn’t there, and others refused to speak her name. When she, as well as Sherrie later on, tried to question precisely where their role model of a sibling had vanished, they were simply once told she’d run off before all other inquires were disregarded. So, of course, for the longest time, they both believed her dead, especially since Charlotte had once also told the latter there were many locations in California where one could hide a corpse for good.

That’s when Charlotte and William were brought in for questioning, just for their statements to further make investigators think Mary had actually been heinously murdered by the latter in 1981 itself. While almost all of the former’s remarks were found to either be baseless allegations or lies, including how she’d reported her daughter missing, the latter conceded he had indeed hurt her that last night. He explained he was 15 on an anger scale of 1-10, so when his stepdaughter had tried to leave their Seaside house in the middle of their fight, he’d gone as far as to subdue her with a chokehold.

William then made it clear that although he doesn’t believe he killed Mary, he doesn’t remember much else apart from the fact his wife had later told him “Satan” was in his eyes during the encounter. He essentially indicated this demon inside him could’ve done the crime, leading officials to return to the scene in 2003 with cadaver dogs — they did detect the scent of human remains in the area. A small child’s shoe was subsequently uncovered from deep within the dirt, on the basis of which local authorities were ready to build a homicide case against both Charlotte as well as William.

However, their plans came to a complete halt on November 25, 2003, as a woman by the official, legal name of Mary Louise Day was pulled over in a routine traffic stop all the way in Phoenix, Arizona. Upon questioning, she claimed to be the same missing Mary who’d run away from home in 1981, yet her ID had only been issued three weeks prior, plus she had an extremely strong southern accent. She also didn’t remember the code word “Mohawk” she had with Kathy in reference to their family escape plan — once they’d turned 18 and had access to some inheritance money, they’d arranged to flee.

Yet, all hypotheses of her being an imposter arranged by Charlotte and William to avoid homicide charges went out the window once DNA analysis basically confirmed she was Mary Day. This test determined she was not just Charlotte’s but also Charles’ daughter; plus, the shoe that had been recovered months prior from the scene was then deemed to be too small for a 13-year-old. The case of Mary was hence closed — her sisters have had their suspicions because she either didn’t want to or couldn’t give a logical explanation of her past two decades, but she did say she’d used the name Monica Devereaux for the longest time.

How Did Mary Louise Day Die?

It was around the mid-2000s when Mary returned to Arizona after spending a year residing with Sherie in North Carolina, during which she’d reportedly tried to overdose with Tylenol several times. According to the latter, she was even an alcoholic and had such drastic behavioral tendencies there was a real possibility she suffered from mental ailments like multiple personality disorder. Unfortunately, things then didn’t improve for her as she ended up tying the knot with someone who turned out to be abusive, and then their relocation to Missouri was marred by her late-stage cancer diagnosis. Mary reportedly remained in Missouri until she passed in 2017.

Read More: Where Are Charlotte Day and William House Now?