After releasing photos and an audio clip of the suspected killer of Liberty German, 14, and Abigail Williams, 13, the Indiana State Police Department has received more than 11,000 tips.

As reported by People, the photos and audio clip of a man’s voice, saying the words “Down the hill” were found on Liberty’s cellphone and reportedly police hailed the teenager a hero for recording what could be potentially crucial evidence in the case.

However, despite the tips received, so far the man who killed the two teenage girls, dumping their bodies near a local creek, has still not been found.

Investigators are, however, confident that they will solve the case and arrest the perpetrator. Sgt. John Perrine said at a press conference Thursday that it is an emotional time for all of them and that it is not easy.

However, he added that a lot of people are putting work into the case and they hope a tip comes in that solves the crime. Perrine added that over $200,000 has been raised as a reward for the identification and arrest of the Suspect.

Liberty’s grandfather speaks out

According to a report by the Chicago Tribune, Mike Patty, grandfather of 14-year-old Liberty, spoke out on Thursday, pleading with the public to look at the evidence released by the police and provide tips to potentially lead to the killer’s arrest.

Patty continued by saying that anyone in the area who has noticed unusual changes in appearance in relatives, friends or acquaintances, like shaving off a beard, or acting strangely, should please contact authorities on the tip line. He stressed that people shouldn’t “second-guess” themselves if they have a gut feeling after noticing something unusual.

Liberty and Abigail were on a hike

The bodies of Liberty and Abigail were found less than a mile from where they were last seen after being dropped off to go for a hike near Delphi, Indiana.

When the families went to pick up the girls at a prearranged pickup location, there was no sign of either girl, leading to a search of the area.

Similarities to another crime in Iowa

Investigators have reportedly spoken to authorities in Iowa about a similar case involving the 2012 abduction and killing of two cousins. That case is still unsolved and involved two girls who disappeared on a trail and were later found dead.

However, Perrine says as yet they do not believe the two crimes are related, despite the similarities. The Evansdale, Iowa, case involved Lyric Cook, 10, and Elizabeth Collins, 8, who disappeared in July of 2012. Their bodies were discovered some months later in a wildlife refuge.

Perrine said so far investigators believe the similarities between the two cases are purely coincidental. However, he said they are “confident and optimistic” that their investigations will lead to finding the person responsible for Liberty and Abigail’s deaths.

Anyone with potentially helpful tips is encouraged to phone 1-844-459-5786 toll free. A photo of the suspect and the audio clip are included below.