It was a story that rocked a nation: A woman answered the door to her Chicago home to find the daughters of her reclusive neighbors — nine-year-old Nicole Schoo and her 4-year-old sister Diana — shivering in the cold. Their parents, they said, had left them for a nine-day Christmas vacation to Mexico.

Connie Stadelmann would later recount that the girls told her their fire alarm was going off and something was leaking.

It was Dec. 21, 1992 — two years after Home Alone had debuted in theaters. But unlike the film starring Macaulay Culkin, this was no comedy.

The girls were the children of David Schoo, a then-45-year-old engineer, and his homemaker wife, Sharon, then 35. They had left one day prior on an Acapulco vacation, telling Nicole and Diana to fend for themselves in the family’s tri-level Tudor-style home — on Christmas, no less.

The girls were not in the care of a baby-sitter, and did not have access to an emergency phone number where the parents could be reached. They were left instead with a stack of frozen dinners, cereal, and a note with instructions on when to eat and when to go to bed.

As Nicole would later recount to a TV reporter, “For a long time I would feel really bad, wondering what they were doing.”

According to the girl, she and her sister had previously been left unattended while their parents spent four days in Massachusetts the prior summer.

After the children arrived at the Stadelmann house, firemen and local sheriff’s department investigators showed up to respond to claims of smoke — they found none but, when they also found no sign of any adults, they started asking questions. The girls were placed with their maternal grandmother and later in foster care while authorities attempted to locate the Schoos. They were finally spotted on Dec. 28, at an airport customs check in Houston, heading home.

Both were charged with two felony counts of child abandonment and cruelty to children and a misdemeanor charge of child endangerment — and the case quickly struck a national nerve.

Media reports described the couple as odd and withdrawn from their own families. David, it came to light, had earned his pharmacy degree from the University of Illinois in 1970, but surrendered his pharmacist’s license eight years later, after admitting to stealing approximately 1,900 high-potency Valium tablets from the Aurora drugstore where he worked. He then turned to engineering.

Sharon, meanwhile was described as “kind of a recluse,” by her own father, who told PEOPLE: “She told her own mother to make an appointment to see her.”

Ultimately, the Schoos were indicted on charges including felony abandonment, neglect, endangerment and cruelty to children. The Chicago Tribune reported that the couple avoided trial through a misdemeanor plea deal and were sentenced to two years’ probation.

The case garnered so much scrutiny that it changed state law, with Illinois lawmakers drafting a law dictating when and for how long a child can be left alone. In 1993, changed the legal definition of child abandonment to intentionally leaving a child younger than 14 alone for 24 hours or longer.

That same year, the girls were reportedly placed for adoption.

Meanwhile, even as the scrutiny died down, others in the neighborhood argued the children belonged elsewhere — and far away from their parents.

As neighbor Bill Stadelmann told PEOPLE of the Schoos, “Forget the jail. Let them go to Acapulco. Let them go to & Europe. Let them do whatever they want. Just don’t let them hurt the kids again.”