Sherrie Calgado was told that her older half-sister Mary Day had run away in 1981.
But that explanation became increasingly insufficient for Sherrie, who was 10 when 13-year-old Mary vanished from her home in Seaside, Calif. So, in 1992, Sherrie reported her long-lost sibling missing.
And she was the first person to do so, according to Seaside authorities, who said in Investigation Discovery's The Curious Case of...The Girl Who Died Twice that there was no record of Mary's mother Charlotte Houle and stepfather William Houle calling police or filing a missing person report in 1981.
"I can't remember a time when a child was not reported by the parents," retired former Seaside Police Capt. Steve Cercone told CBS' 48 Hours for a January 2021 episode dedicated to Mary's fate. Added Sherrie, "I couldn't understand how a mother could not go to the ends of the earth to find her child."
When they finally caught the cold case, it didn't take long for detectives to presume that Mary was dead. Or, more specifically, that someone had killed her.
And they suspected that someone was Mary's stepdad William—who denied as much to police when interviewed in 2003, but also told them that maybe a demon inside of him was responsible.
William and Charlotte have denied any wrongdoing with regard to Mary's disappearance. Sherrie spoke to her mother off-camera and shared in the show that she denied “everything and all of it,” with “no remorse, no contrition, no responsibility.” ID noted that Charlotte, who's living at a Kansas nursing home, refused to be interviewed and William didn't respond to producers' request for comment. (48 Hours stated in 2021 that they got a no comment from the pair through a relative.)
But just as authorities were digging into whether William might be a killer, 22 years after his stepdaughter went missing, a woman who claimed to be Mary turned up in Phoenix, Ariz.
And what happened next is stranger than fiction:
Who Was Mary Day?
Mary Louise Day was born Feb. 19, 1968, in Little Falls, N.Y., to Charlotte Day and second husband Charles Day.
The couple also had daughter Kathy in 1969, after which Charlotte had an extramarital affair that produced Sherrie Calgado in 1971, as Sherrie detailed in Investigation Discovery's The Curious Case of...The Girl Who Died Twice.
Later, Sherrie continued, Charlotte met William Houle—who was barely 18 and ended up enlisting in the Army—and left Charles.
Sherrie recalled she and her sisters spending time in a foster home before their mother married William.
Charlotte eventually regained custody of her children and she and her third husband came to pick them up, Sherrie said, but she purposely peed on her mother in the car as they were all driving away.
So, Sherrie added, they turned the car around and dropped then-6-year-old Sherrie back off with the foster family, who ended up adopting her.
Charlotte and William moved Mary and Kathy to Seaside, in central-coastal California's Monterey County, where he was stationed at the Fort Ord military base.
Sherrie said in the ID show that she remained in touch with her sisters for several years until "one day it just stopped."
She was 12 when she got a letter from Kathy postmarked from New York, indicating the Houles had moved back there, and her adoptive parents took her to visit.
That's when Charlotte told her that Mary had run away from Seaside, Sherrie said. She also recalled Charlotte saying that she didn't have any pictures of Mary anymore, that she'd burned them all.
Why Didn't Mary Day's Parents Report Her Missing?
In 1992, Sherrie took it upon herself to report Mary missing. It's unclear why it took a decade for Seaside Police to open an investigation, but once they did in 2002, the trail soon ran cold.
"Her social security [number] had never been used," now-retired Det. Joe Bertaina, who worked the case, said in the ID show. "You couldn’t find any evidence of her applying or having any identification. And I thought that was very unusual."
Mary hadn't been enrolled in school at the time of her disappearance, either, but she was receiving her deceased father's social security, Charles Day having died in an accident in the late 1970s.
One reason the Houles may not have reported Mary missing, Bertaina surmised to 48 Hours in 2020, was that "they were taking Mary's social security checks and cashing them."
Why Did Police Suspect William Houle of Harming His Stepdaughter Mary Day?
On the ID show, Bertaina detailed that Kathy told him during his investigation that on June 15, 1981—the day before Mary disappeared—she and her sister were home while their mom and stepdad were out, and their family dog, Bubba Brown, got sick.
When William and Charlotte got home, he accused the girls of poisoning the dog, the detective continued, and when a "defiant" Mary "argued back," Charlotte told Kathy to go to her room and close the door.
Kathy went to her room but, instead of closing the door, she told the detective she was able to see William beating her sister, Bertaina said. The next morning, according to Kathy, Mary was gone and, when she asked her mom where she was, Charlotte said she had run away and they weren't going to talk about her anymore.
They briefly moved into housing at Fort Ord, then left the state entirely for Canterbury Hill, N.Y.
What Was Buried at the House in Seaside?
After Kathy also shared with Bertaina that, once Mary went missing, her stepdad forbid her from playing in a certain area of their backyard, police set out to excavate the site.
They brought in cadaver dog handlers from the Bay Area, former Seaside Police Chief Steve Cercone said in ID's The Girl Who Died Twice, and four dogs, sniffing around one at a time, all led them to a particular tree.
Cercone, who was a captain in charge of the investigation at the time, recalled the "unforgettable scene" on the day of the dig when they unearthed a little girl's shoe buried under the tree.
"We thought, Well, we found her, there she is," Cercone said. "It was an emotional moment."
But while they also found a teddy bear and a belt buckle, there was no body. "It was so puzzling," Cercone said.
What Did Mary Day's Stepfather Tell Police About the Night Before She Disappeared?
Next, Bertaina detailed in the ID show that they traveled to Kansas, where William was working as a prison corrections officer, to interview him and Charlotte.
Per footage of Charlotte's interview showed in the episode, she told the detective that her husband had filed a police report with the Salinas Police Department (he did not, Cercone said), but then she also said that they had given Mary a bus ticket to Salinas, Calif.
Cercone called her interview "very revealing," alleging it was "apparent she was worried."
William, meanwhile, told Bertaina that he "may have" hit Mary on the night in question over the dog, according to the detective, but that he blacked out.
"He went on to tell me that Charlotte the following day told him, 'You had a demon in you that night,'" Bertaina said. Asked if he killed Mary, William "said he'd never do that," Bertaina continued, but when the detective asked William if he thought the demon could have done it, "he said, 'Yes, the demon could have killed Mary.'"
Was Anyone Ever Charged in Mary Day's Disappearance?
Cercone said that, while he thought they "had a lot of evidence," they didn't have a body and the district attorney wouldn't consider filing charges against William without more evidence.
Who Was "Phoenix Mary"?
In November 2003, Phoenix police pulled over a truck for having stolen license plates and the woman in the passenger seat presented identification stating that she was Mary Day.
When the Seaside police got word, they were stunned.
"Of course this woman can't be Mary Louise Day," Cercone recalled thinking, "because Mary Louise Day is dead."
Bertaina also had his suspicions, saying in the series that the woman claiming to be Mary "knew basics but not certain things she should know" about her childhood and the events leading up to her leaving her stepfather's house.
"I don't know how I did [get out of the house]," she told the detective, per an audio clip from their interview. "I can't remember day from night."
But a subsequent DNA test confirmed this woman was Charlotte's biological daughter.
Whether she was actually Mary, or another child the family was unaware of, was still a subject for debate.
(On the ID show, Sherrie recalled finding out in her 20s that her mom had a daughter from her first marriage. That half-sibling, Jeannie Parnell, told Sherrie she'd always wondered if Charlotte, being so "promiscuous," had even more kids they didn't know about.)
While Sherrie said that she "started bawling" upon hearing that Mary had been found, once they reunited she immediately had her doubts. She also admittedly hoped that this woman wasn't actually her sister, she recalled, finding her volatile and disheveled at times, though perfectly agreeable and pulled together at others.
For awhile, this Mary lived with (and then near) her in Fayetteville, N.C., Sherrie said, but she eventually returned to Arizona "and I just let it go."
What Happened to Mary Day?
While he was supervising the Mary Day investigation, Cercone was appointed chief of police in Seaside, after which he put Det. Mark Clark in charge.
But Clark, no closer to confirming whether "Phoenix Mary," as they took to calling her, really was the Mary, left the investigation in 2008.
Fast-forward to 2017, when Sherrie found out that the woman she still couldn't believe was her sister was dying of cancer in Warsaw, Mo. She called Seaside's acting chief of police Judy Veloz.
As Veloz, now retired, said in the ID show, she went out to Warsaw and sat down with Mary, who was in hospice, for 90 minutes.
She still "didn't recall" the beating, Veloz said, and "didn't know exactly when or how" she left the house in Seaside in 1981. But she said that she'd been taken in by "an older lady" named B.J. Ward in Salinas.
Mary died nine days after their interview, Veloz said.
She told 48 Hours in 2020 that she was "100 percent convinced" that the woman she spoke to was Mary Louise Day. "No question."
Back in Seaside, Veloz said in the 2025 ID show, she reached out to B.J. Ward, and B.J.'s boyfriend said he thought he might have a picture of Mary in storage.
Looking at the picture a few weeks later, Veloz said, she recognized the missing teen.
She called it "a real piece of evidence that Mary was not killed in 1981," noting that the picture had been taken in 1983. And so, Veloz said, she had "nothing to do but close the case again."
Cercone, however, said that the resemblance wasn't hard evidence—"Sure, it looks like it could be Mary," he noted"—and Sherrie still thinks her sister has been dead for almost 44 years.
"I think my sister Mary Louise Day was killed on a summer day in 1981," she said. "I've felt for a very long time that she's gone."