DELPHI, Ind. (WOWO): A sad milestone: this is the one-year anniversary of the still-unsolved murders of two Delphi teens.

14-year-old Liberty German and 13-year-old Abigail Williams vanished one year ago today while walking on a hiking trail near Delphi. Their bodies were found the next day, prompting a nationwide manhunt for a man photographed by one of the girls’ phones, which also captured this audio clip of him ordering them down a hill.

Police are hoping the anniversary will spur a wave of tips from the public, and hopefully, that will lead to the killer.