“The Delphi Murders: Who Killed Abby & Libby?” premieres tonight at 10 ET on HLN.

Delphi, Indiana CNN  — 

A five-and-a-half-year nationwide search for a suspect in the killings of two Indiana teens ended with the arrest of a local man, authorities said Monday.

How investigators came to arrest 50-year-old Richard M. Allen, of Delphi, will remain a mystery for now, as a court has sealed charging documents and the investigation remains open, but authorities say Allen is charged with two counts of murder in the 2017 slayings of Abigail Williams, 13, and Liberty German, 14.

The pair went for a hike along Delphi Historic Trails in February of that year but never showed up at a previously arranged time to meet Libby’s dad, police said. Their bodies were found the next day in a wooded area near the trail, about a half mile from the Monon High Bridge where they’d been dropped off, according to police. A grainy video of a man walking and a garbled voice recording were among the scant clues authorities publicized over the years.

Neighbors saw police searching Allen’s home two and a half weeks ago, they say. Police arrested Allen on Wednesday, according to a news release, and formally charged him Friday before transporting him to White County Jail. Allen is being held without bail.

“Today is not a day to celebrate, but the arrest … is sure a major step in leading to a conclusion of this long term and complex investigation,” Indiana State Police Superintendent Doug Carter told reporters.

Asked the family’s reaction to news of Allen’s arrest, Carter said, “It was a very sad, yet a very humbling experience.”

Allen pleaded not guilty at an initial hearing, Carroll County Prosecutor Nick McLeland said. He is scheduled to return to court for a pretrial hearing January 13. His trial is slated to begin the morning of March 20, the prosecutor said.

Suspect assisted with funeral photos, aunt says

CVS confirmed that Allen worked for the drug store chain but did not specify where. The company is shocked and devastated, it said in a statement, and stands “ready to cooperate with the police investigation in any way we can.”

Libby’s grandmother, Becky Patty, and aunt, Tara German, were informed someone was in custody Wednesday, and on Friday, they learned it was Allen, who police said worked at the CVS in Delphi, they said. Patty does not know Allen, she said, but German is a regular at the CVS and knew Allen from shopping at the store. She recalled a specific encounter with Allen following Libby’s death.

“I went into the store to print photos of Libby for the funeral, and he was the one who helped me,” German said. “I was a mess trying to get the images off my phone. Once they were printed, he looked at me and said, ‘I’m not gonna charge you for this.’”

While McLeland said a judge had found probable cause to charge Allen with murder, he declined to elaborate on the reasoning, saying the charging documents and probable cause affidavit were sealed. A court will revisit the decision to seal the documents later, he said.

In the meantime, tip lines remain open, he said, and investigators are seeking information “not only about Richard Allen, but about any other person you may have.” McLeland declined to elaborate on whether authorities are seeking additional suspects.

Liberty German, left, and Abigail Williams were killed in 2017.

“I know it’s frustrating,” he said. “My goal is to maintain the integrity of this case.”

Following Monday’s news conference, Carter told HLN he had “already gotten tips directly since 10 o’clock.”

Carter also declined to provide many details, saying, “We are going to continue a very methodical and committed approach to ensure that if any other person had any involvement in these murders in any way, that person or person will be held accountable.”

“This investigation is far from complete,” he added, “and we will not jeopardize its integrity by releasing or discussing documents or information before the appropriate time.”

While details are not yet forthcoming, a couple who lives near Allen and asked not to be named said they saw unmarked police vehicles at Allen’s home October 13. Close to nightfall, a deputy arrived with a sheet of paper, which the deputy showed to Allen before they began searching the house and yard. the neighbors said.

A tow truck took away Allen’s black SUV, they said, and officers exited the home with bundles of cloth or clothing, a stack of books, a shopping bag and a shoebox. They also set up lights in the back yard next to a shed and dug out two small areas, while appearing to use a metal detector, they said. Allen remained outside the home, and his wife left twice, returning the second time after deputies had left.

One of the neighbors asked a deputy whether he should be worried, and the deputy responded, “Just remain vigilant, especially with your wife and daughters.”

Allen never stood out, the couple said. He lives with his wife and cat and rarely has visitors, they said. They frequently saw him in his driveway smoking cigarettes and drinking beer after work, they said.

Long wait for an arrest

It’s been 2,086 days since authorities launched their investigation, Carter said. Abby and Libby set out on a hike at the Delphi Historic Trails during a day off from school February 13, 2017. They never returned.

A search began, and 18 hours later their bodies were found in the woods, near an abandoned railroad bridge they’d photographed during their hike. Abby posted to Snapchat a photo of the girls crossing the railroad bridge shortly before they were killed.

Authorities in 2019 released this sketch of the suspect in Abigail Williams' and Liberty German's killings.

It was another image Libby captured that drew headlines across the country – a grainy, pixelated image of a man in a blue jacket and jeans on the bridge. Indiana State Police investigators released the image, saying they believed the man was a suspect in the double homicide.

State police also released audio of the alleged killer saying four words – “… guys … down the hill” – in hopes the public might identify the suspect’s voice.

In 2019, police released a new sketch and additional video from one of the girl’s cell phones.

The killings devastated Delphi. Investigators received a dozen or more tips every day, McLeland said in 2019. Libby’s grandparents, Mike and Becky Patty, issued an appeal for help in 2021.

“We are stuck in time looking for a monster that murdered two young girls. We are only asking for one minute out of your day,” they wrote in a letter to the public. “If it was your child or loved one, would you think that is too much to ask?”

In December, the Carroll County Sheriff’s Office and Indiana State Police asked for the public’s help regarding the social media profile for “anthony_shots,” which they said was used from 2016 to 2017 on Snapchat, Instagram and possibly other social media sites.

The catfish account “used images of a known male model and portrayed himself as being extremely wealthy and owning numerous sports cars,” a news release said. “The creator of the fictitious profile used this information while communicating with juvenile females to solicit nude images, obtain their addresses, and attempt to meet them.”

Tokens sit in the snow at a memorial along the Monon High Bridge Trail in Delphi earlier this year.

Investigators have identified the model, and “he is not a person of interest in the investigation,” they said. Detectives, however, are seeking information about the person who created the profile.

Last week, Cynthia Rossi, a friend of Abby and Liberty who grew up near them, expressed hope that Monday’s announcement would provide closure.

“I’m glad that justice will be served, hopefully, that that’s what the news is, but a part of me will always have died with them that day, and a part of me will never fully find peace and justice,” Rossi said.

Added Delphi resident Shirley Goyer, “There’s a lot of people that will be there. We’ve been waiting for this, so it’s a good thing that we’re finally getting to the end of it, I hope.”

HLN’s Barbara MacDonald reported from Delphi, CNN’s Emma Tucker wrote and reported from New York and Eliott C. McLaughlin wrote and reported from Atlanta. CNN’s Amanda Watts contributed to this report.