Authorities released video Monday of a man suspected of killing two Indiana teenagers in 2017 and urged the public to scrutinize the footage, which shows the man walking on an abandoned railroad bridge the girls visited while out hiking the day they were killed.
The Indiana State Police also released a new sketch of the suspect, which State Police Superintendent Doug Carter said was produced thanks to "new information and intelligence" collected during the investigation into the killings of 14-year-old Liberty German and 13-year-old Abigail Williams.
During a briefing in the girls' hometown of Delphi, he said that a composite sketch that was previously released based on accounts from eyewitnesses who believe they saw the man is now secondary to the new sketch.
Carter said investigators believe the man is between the ages of 18 and 40, and that he either lives or lived in Delphi or regularly visits or works in the area. He vowed that police will solve the case and, during the briefing, he addressed the suspect directly.
"We believe you are hiding in plain sight. For more than two years, you never thought we would shift gears to a different investigative strategy, but we have," he said.
The video of the suspect and additional audio that was also released Monday came from German's cellphone. Authorities have hailed her as a hero for recording potentially crucial evidence before she was killed.
Carter urged the public to pay close attention to the mannerisms of the man in the video, which shows him walking across an abandoned railroad bridge near Delphi, a community of about 3,000 people roughly 60 miles northwest of Indianapolis.
The bodies of the girls were found in February 2017 in a rugged, wooded area after they went hiking near Delphi.
Investigators said they were dropped off near an abandoned railroad bridge to walk around and "hang out." The girls were supposed to be picked up later in the afternoon, but did not show up there at the previously arranged time.
Following an extensive search, the bodies of the two girls were found the next day approximately one-half mile upstream from the bridge, authorities said.
Police have not released details of how the teens died.
Within days of the killings, investigators released two grainy photos of a suspect walking on the bridge and an audio recording of a man believed to be him saying "down the hill."
The audio clip released Monday includes that same audio but is longer and captures the suspect saying, "Guys, down the hill," said Sgt. Kim Riley with the State Police.
Investigators have reviewed thousands of leads looking for the man, but no arrest warrants have been issued and no arrests have been made.
During Monday's news conference, Carter spoke directly to the suspect.
"The question to you: What will those closest to you think of when they found out that you brutally murdered two little girls, two children? Only a coward would do such a thing."
He added, "We have a witness. You made mistakes. We are coming for you and there's no place for a heartless coward like you to hide that gets his thrill from killing little girls."
The Associated Press contributed to this report. This story was reported from Los Angeles.