Delphi Murders: 5 Years Later, Victim's Sister Clinging to Hope That Killer Will Be Caught

Kelsi German tells PEOPLE she holds "a lot of faith" in the detectives investigating the 2017 murders

Libby German and Abby Williams. Photo: Courtesy Mike and Becky Patty

Five years ago today, in Delphi, Ind., two best friends, Abigail Williams, 13, and Liberty German, 14, went missing while on a hike through the city's historic trails. The next day, the girls were found murdered — likely by the strange man Liberty managed to record audio and video of with her smartphone.

Five years later, the investigation into their murders remains very much active, with authorities requesting only days ago that the public come forward with specific information on an individual who's now behind the bars of an Indiana prison.

Kelsi German, Liberty's sister, tells PEOPLE anytime investigators release new information on the case, "that's a new piece of hope, you could say. We are all hopeful that it means something, and we will continue to share the information the police ask us to share."

Days after Liberty and Abigail's deaths, authorities released photos that had been taken from Liberty's phone that showed a man on the trail, walking behind them. A brief audio clip of his voice — also pulled from the girl's phone — and a police sketch of the unidentified man were also released.

The unknown man has been dubbed the main suspect in the girls' murders.

On Thursday, state and county authorities announced that investigators "continue to work diligently to bring this case to a close." Specifically, investigators want to speak to anyone who may have "communicated with, met, or attempted to meet" a man named Kegan Kline.

Authorities allege that Kline utilized a male model's pictures to create an Instagram profile — anthony_shots — he then used to solicit nude images from young girls.

According to investigators, the anthony_shots profile was active on Instagram in 2016 and 2017.

"Please provide as much information as you possibly can," the release urges. "For example, when you communicated with anthony_shots, how you communicated with the profile, what social media applications the account used, and if anthony_shots attempted to meet you or obtain your address."

It continues: "If you have saved images or conversations with the anthony_shots profile, please attach them to your email."

Kline is being held in Florida on 30 criminal counts, including possession of child pornography, child exploitation, child solicitation, and synthetic identity deception — charges he's pleaded not guilty to.

Kegan Anthony Kline. miami county sheriff’s office

More than a week after Abby and Libby were killed, authorities executed a warrant at the Peru, Ind., home where Kline and his father lived. However, they found nothing to connect him to the Delphi killings.

Kline has not been charged with the murders.

Kelsi tells PEOPLE she's not so sure Kline is the killer.

"They never told us how or if he is connected," she says. "I'm not sure this guy is the guy, but they are looking very hard into this account. For whatever reason, they think the account is important."

Regardless, she says she and her relatives will always share whatever information police ask them to.

"I think right now our focus is to continue to share this anthony_shot's profile," she says, "and ask people that if they have had any connection with that account, that they come forward and let police know so they can get all of the information possible to get us where we need to be."

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Kelsi, who graduates from Purdue University in May and heads down the altar in June, can't help but hold on to hope, she says.

"We hold a lot of faith in our detectives, because they do constantly tell us they are working as hard as they possibly can, using all of their resources, and we trust them in that," Kelsi says.

"We are able to get updates from them, which is helpful to us," she adds. "The fact that they are releasing information, that they're talking about the case, let us knowing they're working on it ... it gives us a continued hope this will be the year for justice."