On February 13th 2017 13 13-year-old Abigail "Abby" and 14-year-old Liberty "Libby" had planned to go hiking along the Delphi Historic Trail. Libby's older sister dropped the teens off near the trail. 

"They just got out of the car and walked down the trail to go to High Bridge. We told each other we loved each other. And that was the last time I saw her" - Libby's older sister

At 2:05 pm Libby posted a photo on Snapchat of the Monon High Bridge. Two minutes later she posted a picture of Abby walking across the bridge. Nobody knew this would be the last correspondence from either teen. 

As the night grew older, the teens' families began to worry about them. Since there was no sign of the two, they were reported missing. 

On the following day, the 14th, volunteers and law enforcement began a search for Abby and Libby. They spent hours canvassing the area for any signs of the two girls. Eventually, two bodies were found in a rugged area in the underbrush near the Monon High Bridge. These two bodies would be confirmed to be Abby and Libby on the following day. State police released images discovered on Libby's phone to the public, saying they were believed to be of the suspected killer.

The following days after the murders, police started releasing images and videos from Libby's phone. One of these images is of a man walking on the bridge with his head bowed down and hood up. Indiana State Police also released an audio recording to the public of a male voice saying, "Down the hill."

On July 17th the police released the first sketch of what the potential suspect could look like. This sketch however was discarded as in 2019 the police released a new sketch along with a video and extended audio extracted from Libby's phone. Police clarified the second sketch is not the same man as in the first sketch. 

Anthony Kline

Towards the end of February 2017, ISP and FBI searched Libby's phone. Turns out, the 14-year-old had been in contact with a used by the name of "anthony_shots" on Snapchat. He was identified as Kegan Anthony Kline. Kline told police he'd used social media accounts to talk to underage girls, contacting both people he knew and didn't know. He told police he would find girls on social media. Kline said he had about 100 pictures from underage girls that were sexual, in addition to about 20 sexually explicit videos.

In August 2020 he was charged with 30 felonies, including possession of child pornography, child exploitation, obstruction of justice, child solicitation and synthetic identity deception.

Despite all of this, he has not been charged with the murders of Abby and Libby. 

Unnamed suspect

On July 23, 2019, a suspect wanted for a kidnapping and rape in Tippecanoe County was named as one of multiple suspects being investigated for the Delphi murders. He however had died by suicide the previous month.

Nothing came of this. 

Odinist Cult theory

In 2023 while Richard Allen (see below) was in the court, his legal team came up with a theory of Libby and Abby being killed in relation to an odinist cult. This theory was quickly overruled by the judge. 

Daniel J. Nations

In September 2017 Nations was pulled over for driving with expired plates. The officer found a rifle in the car. He was also wanted in connection with complaints of a man threatening hikers with a hatchet in Woodland Park. A mountain biker, Timothy Watkins, was fatally shot on the trail around the same time Nations was allegedly threatening people.

Nations had a lengthy criminal record, including petty offences and domestic violence, as well as being a registered sex offender after being charged with indecent exposure. In early February 2018, police announced that Nations was no longer considered an active person of interest in the Delphi murders.