CHICAGO (CBS) — Indiana authorities have received more than 2,700 tips about the 2017 murders of 13-year-old Abby Williams and 14-year-old Libby German since releasing a new sketch of the suspect, along with more audio and video evidence.

Since releasing new details of the case two weeks ago, a multi-agency task force in Indiana has received more than 2,200 emails and 400 phone calls, along with 135 additional tips provided to local and state police.

Abigail Williams (left) and Liberty German (right) (Credit: Facebook)

Overall, Indiana State Police said there have been more than 42,000 tips provided since the two girls were slain in February 2017.

Abigail J. “Abby” Williams and Liberty Rose Lynn “Libby” German disappeared while they were hiking on the Monon High Bridge Trail near Delphi in February 2017. Their bodies were found a day later on Valentine’s Day in a wooded area a quarter-mile from an abandoned railroad bridge that’s part of a trail system where the teens had planned to go hiking during a day off from school.

More than two years later, there have not been any arrests.

Sketch of suspect in murders of two Indiana teens. (Credit: FBI)

Two weeks ago, investigators released a new sketch of the suspect. They also released a short video clip and a longer audio recording of the suspected killer captured on Libby’s cell phone.

The new sketch released on April 22 is significantly different than the one released two years ago.

An old sketch of the suspect shows him wearing a hat, and with facial hair, but the new sketch shows him clean shaven, with no hat. The facial features — including the shape of his chin, eyes, and nose — also are much different in the new sketch, but police did not explain the changes.

Indiana State Police Supt. Douglas Carter said he believes the girl’s killer is “hiding in plain sight.” He said police are looking for the driver of a vehicle abandoned on County Road 300 North next to the Hoosier Heartland Highway on the day the girls disappeared. The vehicle was parked at the old Child Protective Services/Department of Child Services/Welfare building in Delphi.

Carter said investigators believe the killer is 18 to 40 years old; and is either from Delphi, works there, or is a regular visitor.

Police also have released a brief video clip of the suspect recorded on Libby’s phone, showing him walking down a railroad bridge, wearing a blue jacket, jeans, and a hat.

An audio recording from Libby’s phone also caught the man saying “guys, down the hill,” a slightly longer clip than the one released days after the girls’ deaths.

Anyone with information about the should send tips to abbyandlibbytip@cacoshrf.com; or call the FBI tip line at 844-459-5786, or Indiana State Police at 800-382-7537, or Carroll County Sheriff’s Department at 765-564-2413.