In 1981, 13-year-old Mary Day disappeared from her Seaside, Calif., home, with no sign of her anywhere. It would be 22 years before she reappeared, bringing along more questions than answers.

Mary Louise Day was born on February 19, 1968, to Charlotte Pressler and Charles Day in Little Falls, New York.  

The Day girls

Within the next three years, the Day family grew with the birth of Mary's sisters, Kathy, left, and Sherrie, center. Mary is pictured on the right

A difficult childhood

Life wasn't always easy for the family. Mary, right, Kathy, center, and Sherrie, left were in and out of a foster home.

A new stepfather

While the girls were in foster care, Charlotte divorced Charles Day and married William Houle, who enlisted in the Army soon after. 

Sherrie adopted

In 1976, Charlotte retained custody of daughters Mary and Kathy Day, but Sherrie, right, was adopted by the foster family, separating the sisters. 

A new family

While Mary and Kathy Day  were still in foster care, Charlotte and William Houle had two children of their own – Billie Jean and William Jr. In 1978, William Sr. was assigned to a base in Hawaii and the family moved together

The inheritance

A few months after the Houles moved to Hawaii, Charles Day passed away and left an inheritance to his daughters, Mary and Kathy. According to Kathy, she and Mary used a secret code word when talking about the inheritance: "Mohawk." 

William and Mary

Mary Day ended up in protective custody in December 1980 while in Hawaii. Detectives say that her stepfather, William Houle, had been reportedly physically abusing her. 

Off to California

In January 1981, the Houle family, without Mary, moved to Seaside, California, when William Houle was reassigned to Fort Ord. But a few months later, Mary, pictured in red at at left, was released from protective custody and moved back in with the Houles. 

The last night

One night in 1981, the Houles went out for dinner but left Mary at home. When they returned, William Houle's beloved dog was sick. Believing Mary poisoned the dog, William beat her, he admitted to police.The next morning, according to Kathy, Mary was gone. 

Where's Mary?

According to Kathy, she asked her mother, Charlotte, where Mary was.Charlotte told Kathy that Mary ran away and to never ask about her again. 

A sister's concern

Sherrie Calgaro told "48 Hours" that when the Houles relocated to New York, she went to visit them. When she asked about Mary, Charlotte told her Mary ran away. Kathy told Calgaro, "We're not allowed to talk about Mary." Sherrie, who was 10 when Mary disappeared, was concerned. As an adult, she filed a missing persons report in 1994.

The search for Mary

Seaside Police launched their investigation when they received the case in 2002. An age progression photo was generated through the National Center for Missing and Exploited Children.

Back to the house

Seaside Police Detective Joe Bertaina was asked to lead the investigation into Mary Day's disappearance. In 2003, he took Kathy back to the Houles' home in Seaside: Mary's last known whereabouts. Kathy Pires showed the detective a corner of the backyard where she said her parents told her not to play.   

A girl's shoe found

Detective Bertaina's captain, Steve Cercone, brought in a team of cadaver dogs to search the backyard. All four dogs alerted on the specific corner where Kathy says she was not allowed to play. When the team started to dig, they found a little girl's shoe. 

Charlotte Houle speaks

Police tracked down Charlotte and William Houle in Kansas. Charlotte agreed to speak to local detectives about the case. Throughout the interview, she maintained Mary had run away.

Phoenix Mary

After finding the shoe and speaking with Charlotte and William Houle, detectives thought they had a homicide on their hands. Then, the case took an unexpected turn. Nine months after interviewing the couple, a woman in Phoenix, Arizona, was pulled over during a routine traffic stop. Police said it was Mary Day.

Mary's story

In his interview with "48 Hours," Detective Bertaina spoke about traveling to Phoenix to meet Mary in person. He recalled the awful memories Mary had, but it was the memories Mary could not remember that he found troublesome.   

The DNA test

In his interview with "48 Hours," Steve Cercone said he wasn't fully convinced this person was the real Mary Day. He thought she might be an imposter, but a DNA test was ordered and the results came back positive

Sisters reunite

With DNA proving Mary's identity and the case closed, Sherrie Calgaro invited Mary to move in with her in North Carolina. In this photo, sisters Sherrie, Kathy, center, and Mary were reunited.

Doubts remain

After Mary moved in, Sherrie Calgaro started to have doubts over whether this was her sister. This Mary had a southern accent, which Sherrie and detectives found unusual for someone who didn't grow up in the south. Calgaro also found her sister's magazines that were addressed to someone named Monica Devereaux.

Kathy's doubts

Kathy Pires had her own doubts. She claims that this Mary didn't remember that their birth father, Charles Day, had left them an inheritance. Phoenix Mary also didn't remember their code word for it, "Mohawk." 

Case is reopened

In 2008, cadaver dogs, in an unrelated search, alerted near a home in Fort Ord where the  Houles moved to shortly after Mary's disappearance. Steve Cercone, by then the Police Chief, hired Mark Clark, pictured, a retired homicide detective, to look into the case. Clark told "48 Hours" correspondent Maureen Maher he was convinced there was a murder, and that Phoenix Mary was an impostor. 

A new look

In 2017, with Mary's health failing, Judy Veloz, then acting chief of the Seaside Police Department, took a look at the case. Veloz told "48 Hours" she traveled to Mary's home in Missouri to speak with her face to face.

Mary's teen years

Mary told Judy Veloz about a woman she stayed with not long after she ran away – Morie Kimmel. Kimmel says Mary won her heart and she took care of Mary for a year, before she ran away again.

Unseen photograph

While Judy Veloz continued to track down the details of Mary's life after vanishing, one of Morie Kimmel's relatives had a photo that would help turn the case around:a photo of Mary taken at least a year after the alleged murder, seen here in the middle. With this photo, Veloz submitted her report and closed the Mary Day investigation for good.

Finding closure

In 2017, '48 Hours" was there when Sherrie Calgaro, who still had doubts, visited Phoenix Mary in Missouri. Calgaro was still in search of answers. After the meeting, Calgaro told correspondent Maureen Maher that she found her answer – that the mysterious woman is her sister, Mary. Not long after this visit, Mary passed away.

Feeling torn

After reading Judy Veloz's report, Mark Clark admits that it made him second-guess his investigation. But even though he can't prove his imposter theory, he can't quite shake his old hunch.  

Who is buried there?

Steve Cercone leans towards the identity of Phoenix Mary being the actual Mary Day after reading Judy Veloz's report. Still, he wonders about the cadaver dogs and asks if that was not Mary buried in the backyard, who was?