"I can't even believe this is happening."

So said the woman heard on the 9-1-1 call made on the morning of April 12, 2018, and obtained by North Carolina's WNCN-TV.

The voice on the recording belonged to the mother of 43-year-old Steven Pladl, who, according to police, phoned his mom and confessed to killing three people before fatally shooting himself. All of which sounds like a nightmare, but the identity of the victims and the disturbing series of events that led up to the slayings make the story all the more horrifying.

The deceased included Steven's 20-year-old daughter Katie Pladl and her 7-month-old son Bennett Pladl. Police said Steven was Bennett's father, which had resulted in both he and Katie being charged with incest several months before the murders. Also among the dead was Katie's adoptive father, Anthony Fusco, 56.

"Events like this are not common in our community," Knightdale, N.C., Police Chief Lawrence Capps told reporters at the time. "Unfortunately, they are not uncommon in society. We are heartbroken and saddened over the death of this child, and like you, we are trying to make sense of all the factors that led up to this senseless taking of life."

As evidenced by the podcasters and TikTok sleuths who've been revisiting the case ever since, people are still trying to make sense of it all.

Who was Katie Pladl?

Steven's ex-wife, Alyssa Pladl, met Steven online when she was 15 and he was 20, she told the Associated Press after the murders. In January 1998, they had a daughter they named Denise, but they put her up for adoption when she was 8 months old because, Alyssa said, she believed Steven had been abusing the baby. 

"It was so hard to give her up," Alyssa said, "but I had to because I wanted her to live and be happy."

Denise was renamed Katie by Anthony and Kelly Fusco, who also had a biological daughter. Katie's uncle Cary Gould described the family's life as "very, very normal."

But when she turned 18 in 2016, Katie—who loved to draw and had expressed her desire to go to college and work in digital advertising—decided she wanted to meet her birth parents. 

That August, Cary told the AP, she moved in with Steven and Alyssa.

According to Alyssa, Steven emotionally and verbally abused her for years and their marriage was already on the rocks when Katie moved into their Richmond, Va.-area home. Alyssa said she warned Katie that Steven had abused her when she was a baby, and that's why they put her up for adoption.

When did Steven and Katie Pladl's relationship turn incestuous?

Steven started sleeping on the floor of Katie's room about six weeks after she came to stay with them, Alyssa shared with the AP. He told Alyssa to mind her own business and stormed out of the house when she asked him about it, she recalled. According to an arrest warrant later issued for Steven and Katie in Henrico County, Va., he and Alyssa legally separated in November 2016 and she moved out. 

Alyssa told police that she found out in May 2017 that Katie was pregnant by reading about it in her 11-year-old daughter's journal, according to WTVD's reporting on the warrant's contents. 

The warrant detailed that the 11-year-old also wrote about her father telling her and her 6-year-old sister to start calling Katie their stepmom. Alyssa told police, per the warrant, Steven admitted to impregnating Katie when she angrily called him. "I was just cursing him out," she told the AP. "'How could you? You're sick. She's a child.'"

And then she called the police to report him.

Steven's lawyer Rick Friedman II characterized Katie and Steven's relationship as consensual. "This case is an 18-year-old girl who shows up at the doorstep of a 40-year-old man who's going through difficult times with his wife," he told the AP. "They have a bond because they're biologically related, but they never knew each other before they had a sexual relationship. He was head over heels in love with her, so much so that that outweighed the issue of them being biologically related."

How was Steven Pladl able to marry his daughter Katie?

Records reviewed by the AP showed that Steven and Katie obtained a marriage license with falsified paperwork—it said they were unrelated—and wed in Parkton, Md., on July 20, 2017.

Bennett was born on Sept. 1, 2017. According to WWBT-TV, Katie had posted pictures on Facebook of her and Steve holding their baby, as well as shared a photo of them on Instagram with the hashtags #JustMarried and #pregnant.

Steven and Katie moved into a house in Knightdale, N.C., but they were arrested Jan. 27, 2018, by Virginia authorities on charges of incest, adultery and contributing to the delinquency of a minor. Bennett was placed in the custody of Steven's mother, according to Knightdale police.

"I do think she was manipulated," Alyssa told WWBT of Katie, "and I do want her to get help instead of more jail time."

Neither Katie nor Steven entered a plea at their Feb. 20 arraignment.

What happened to Katie Pladl and her son Bennett?

After she was released on bond, Katie moved back in with her adoptive parents in Dover, N.Y., according to her uncle Cary. A preliminary hearing in her case was set for April 23, 2018.

But on April 12, local police said they found Katie and her adoptive father shot to death in his pickup truck in New Milford, Conn., at around 8:40 a.m. after responding to reports of gunfire. Not long after, according to New York state police, a probation officer spotted Steven's blue Honda Odyssey idling in Dover, a few miles away from the crime scene, and notified emergency services. Steven was inside, dead of a self-inflicted gunshot wound, according to Knightdale police, who confirmed the identities of all three bodies. 

New Milford police also said they'd recovered an assault-style rifle that appeared to be the weapon Steven used to kill Katie and Anthony, opening fire on them when they were stopped at an intersection, and then himself.

Meanwhile, Steven's mother had called 9-1-1. "He said he left the baby dead," she told the dispatcher, per the recording obtained by WNCN, also noting that Steven had been upset because Katie broke up with him the day before. "He told me to call police, not to go over there."

Knightdale police said the distraught grandmother had last seen Bennett alive the night of April 11 when Steven picked the child up, telling his mother that he planned to Skype with Katie—who he wasn't supposed to have contact with, per the terms of his bond—that night. At around midnight, police continued, Steven called his mother and said he was going to take Bennett to New York, and then at 7 a.m. he called again and said they were almost there. But then, according to police, he called for the last time at 8:45 a.m. and said he'd killed Katie, Anthony and Bennett.

Arriving at around 9 a.m. on April 12, officers said they found Bennett's body at the Knightdale home where Steven and Katie had been living before their arrest. No one else was in the house.

Steven's attorney Friedman told WRAL after the killings that his client hadn't shown signs that he was about to do anything rash when they spoke a week ago, that he had asked the lawyer's advice about what to wear to court. Steven and Katie were each facing a potential 10-year prison sentence if convicted of felony incest, but Friedman said he had doubted the case would go to trial.

"Deciding how to punish someone for this case is difficult," he said. "How do you punish a biological parent? By putting that parent in jail, and keeping that parent away from the child?"

Calling what transpired "sad and devastating," Knightdale Police Chief Capps said, "We may never understand the mindset or motives of Steven Pladl, but we do know his actions have shattered the lives of countless people."