DELPHI, Ind. (WOWO): An app could help solve an ongoing murder investigation that caught the nation’s attention almost four years ago.

14-year-old Liberty German and 13-year-old Abigail Williams were murdered on February 13th, 2017 near a hiking trail just outside of Delphi.

Since then there have been photos, sketches of the suspect, and even video and audio of him released, but no arrests.

Now an app called CrimeDoor, which uses computer-generated images to give users a sense of being there, could help bring about new leads. The app charges $1.99 to let you digitally walk through a crime scene and look at the same evidence police have seen, according to the Journal and Courier.

You can find the app here.