The haunting final image of Abbie, taken by her friend Libby, and posted on Snapchat.
When night falls in Delphi, Indiana, and the porch lights switch on, orange bulbs cast their light towards the street.
The bright orange glows to honour the memory of two young girls snatched and killed in unimaginable circumstances. They are also a burning reminder that their killer is still out there.
After Liberty German, 14, and Abigail Williams, 13 were found murdered on February 14, 2017, Libby's mother began the movement, encouraging locals in the town of around 300 residents to replace their porch lights with orange bulbs in honour of the girls, reports News.com.au.
They will stay until their killer is caught.
"I pray for the day we can turn off our orange light bulbs," the woman who took the cause to heart and secured 2500 of the bulbs for locals, Paulette Ferguson, says.
But a year on, the bulbs still burn stubbornly bright. As does the memory of two vibrant young teenagers and the desire to catch whoever cut their lives brutally short.
Libby and Abby were best friends, a mateship forged as teammates on the school volleyball team. A couple of days before their fateful hike, the girls had pulled out their softball gear, getting ready for spring practice.
Libby was the louder of the two: outgoing, smart, a "band geek", close to her mum. Like Abby, she played saxophone. She dreamt of being a science teacher.
Abby was a little quieter around strangers, but found full voice among her friends.
One friend, Arika Gibson, said Abby dreamt "of doing something within forensics and police work".
When the friends set off on February 13 for a carefree hike on a day off from Delphi Community Middle School, there was no reason to believe they wouldn't come home.
The weather was great, they knew the local hiking trails, and had arranged to be picked up when they'd finished.
Not long after Libby's older sister, Kelso, dropped them off at the start of the trail about 1.30pm, they were posing for and posting pictures to Libby's social media account.
Under a sunny February sky, Libby uploaded a picture of her friend walking on the Monon High Bridge to her Snapchat at 2.09pm. She could not know how haunting that picture would become.
Libby's grandfather called her mobile just after 3pm, to say he was almost there to collect them and that they should head to the pick-up point.
At 4pm, he called Becky Patty to tell her the girls were not at the pick-up point and Libby wasn't answering his calls or voicemails.
There were prickles of worry, but in Carroll County the idea that two teenagers would be snatched from a trail and murdered was unthinkable. Perhaps they'd fallen and injured themselves? Maybe they were lost?
By 5.30pm, the worry boiled over. The girls were reported missing.
By 6pm, most of the town had joined police in the search: hundreds of people with flashlights, walking the trails in groups.
As the darkness deepened, they agreed to try again tomorrow.
Things might look better in the morning.
But in Delphi, late morning on February 14, things got unimaginably worse.
The girls' bodies were found on the banks of Deer Creek, about one kilometre from where that Snapchat picture had been taken on the bridge. Police have never released details of how they were killed.
As they launched a double homicide investigation, the grieving and the shock rose up. More than 700 people attended a prayer vigil that night at Delphi United Methodist Church.
And the manhunt began.
Nobody knows exactly what happened that day, but certainly, the teens knew they were in danger.
Police believe as the pair were snatched, Libby silently used her phone to desperately record the horror.
On February 15, police released a blurry photo taken from Libby's mobile phone that depicted a man walking along the tracks.
A week later, the FBI released a short audio clip of a man saying "down the hill."
They said the audio came from a video recording on Libby's phone of a man who was following them.
They released a sketch of what the suspect may look like, based on a witness who came forward who had been in the Monon High Bridge Trail area that day.
Police have indicated Libby's phone contains more evidence relating to the suspect, but it will not be released so as not to "compromise any future trial".
Thing like this don't happen in the tight-knit small town of Delphi, which had never seen a crime like it.
The tight-knit community was reeling — it mourned with the families, grieved the girls' deaths, and shocked and angry, wanted answers.
Some, horrified that the killer might be among them, turned detective.
They searched the trails for clues. Libby's grandfather, Mike Patty, would return again and again to the trails "just scanning the woods and creek bank looking for clues and items and anything I could find that would possibly help catch this guy".
As speculation and gossip ran rife, authorities appealed to locals numerous times to quit the armchair sleuthing.
"As we continue the investigation into the deaths of Abby and Libby, please refrain from posting pictures on social media sites of innocent people set side-by-side with the sketch and picture of the alleged suspect," the Indiana State Police asked again on Twitter recently.
"By doing so, you take away from the investigation by slandering and possibly hurting those people and their families".
The locals dropped in food for the police and detectives working all hours on the case.
A year on, sketches of the suspect are blown up in many shop windows. Teal and blue ribbons — the girls' favourite colours — surround the local courthouse.
The school of 360 students looks after each other.
There'll be no assemblies or memorials at school for the one-year anniversary.
Instead, they'll reinforce the message, a year on, that it's "OK not to be OK," says school counsellor Angela Bieghler.
The #FBI seeks info on murder of Abigail Williams,13, & Liberty German,14, in Delphi, Indiana, on February 13, 2017: https://t.co/MD9w0s8pYy pic.twitter.com/QpPxcDxshs
— FBI Most Wanted (@FBIMostWanted) February 22, 2017
Police set up a special force to investigate the killings as Delphi reeled.
News of the girls' slaying brought offers of help from law enforcement agencies across the state and from the FBI, to help out Carroll County Sheriff Tobe Leazenby's department of 11 officers.
They set up in a building near the local courthouse as tips and leads poured in by the thousands.
A year on, the tips and leads number more than 11,000. There's at least one new one every day.
As days turned to weeks, and weeks to months, the number of investigators dwindled as officers returned to their home departments.
But multiple agencies, including the FBI, continue to work the case every day.
Sheriff Leazenby is adamant it's "not a cold case, because a true cold case has nothing left to follow".
"You just can't clear out thousands of leads in a 10-month time period," Leazenby said late last year. "I wish I could give a timeline when we will have exhausted all the tips and leads."
Leazenby says there have been moments he believed the team was close to getting the killer.
"A few of them, we got us wound up," he told Journal and Courier last week.
He won't expand on what those moments were, maintaining the tight-lipped approach investigators have taken since the beginning.
"When people ask, 'Why is it taking so long?', I'm confident when I say that I know one day we'll end up in that courthouse and someone will be standing there being prosecuted," he said.
"I fall back into the fact that when we get that one piece of evidence — and we're going to get it — we're only going to get one shot at a conviction."
The "down the hill" audio continues to be widely circulate with Indiana State Police hoping someone, somewhere, recognises the suspect's man's voice.
In September 2017, a possible suspect was identified with the arrest of Daniel J. Nations in Colorado. He resembled the composite sketch of the suspect, was wanted in Indiana and had been arrested for making threats on a Colorado trail in September.
Police have not said he's considered a suspect in the double homicide, though Indiana police last week brought him back to Johnson County, where he was jailed for failure to register as a sex offender in Indiana and was driving a car with expired Indiana license plates at the time of his arrest.
The loss is as raw as ever for Libby's and Abby's families, who speak out to keep the crime fresh in people's mind, and the hunt for the killer ceaseless.
On Tuesday night they'll hold a candlelight vigil for their lost girls.
They live with the constant thought that "maybe today is the day" the murderer is found, they told NBC's Megyn Kelly Today last month.
"It's a very tough situation to live with, and we have a very small, tight-knit community and to think that this person is still right there in our own back yard is overwhelmingly horrible," said Abby's mother, Anna Williams.
She knows her daughter would not have gone quietly.
"If she was going to go down the hill, it would have had to been, like, super-forcing her to go down the hill," she said.
"She would have tried to fight back or something if he didn't."
In an appearance on Dr Phil last year, Libby's grandparents, said the audio clip, the sketch of the suspect and the pictures of Abby around their home spur on their search for the killer.
"We aren't the type of people to just sit around ... so we have tried to spread the word," Mrs Patty said.
"Our goal is to get his face out there ... everywhere and to every town that his face isn't staring at him.
"We have a hole in our family."
Abby's mother's says there are days she'd "rather just not be here".
"Every day it's brand new and it hurts just as bad as the day it happened," she told Dr Phil.
Her greatest fear is in ten years. she still won't know who killed her daughter.
And still, the orange lights burn.
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