A reward of more than $230,000 is being offered for information leading an arrest and conviction in this case.
The sketch is "an artist's composite of the information" collected by all the agencies involved in the double-murder investigation, including the FBI, said Indiana State Police Sgt. Kim Riley. Riley said investigators consider the sketch a "very important" development in the ongoing investigation.
"It will give people a clearer image of who we are looking for," Riley said.
The suspect is described as a white male with reddish brown hair. His eye color is unknown. He is between 5 ft. 6 in. and 5 ft. 10 in. tall and weighs around 180-220 lbs. The hat in the sketch may not be accurate, police said.
Fourteen-year-old Liberty German vanished with 13-year-old Abigail Williams on Feb. 13 while hiking near Delphi, about 60 miles (100 kilometers) northwest of Indianapolis. Their bodies were found the next day in nearby woods. No arrests have been made in the slayings and authorities have not disclosed how the girls were killed.
Investigators released two grainy images in late February of a man they consider the main suspect in the killings. They also released audio of a male saying "down the hill."
That evidence came from German's cellphone. Riley said investigators believe the man captured in the photos killed both girls.
Anyone with information regarding the murders or suspect should call the tip line at 844-459-5786 or email firstname.lastname@example.org. Tipsters may remain anonymous.
WLS-TV contributed to this report.