Police will announce an update in the mysterious Delphi, Indiana, double murder case on Monday.
The press conference is set for 10 a.m.
Libby German, 14, and her best friend Abby Williams, 13, were on a hiking trail in rural Delphi when they were killed on Feb. 13, 2017.
Police have never named a suspect or released how the girls died.
In 2017, authorities released a grainy image of the suspect, who they say was on the trail the day the girls went missing. In 2019, police released a brief video clip -- footage taken from Libby's phone -- showing a grainy image of the suspect walking on the bridge near where the girls were last seen.
Police also publicized the suspect's voice -- a recording of him saying "guys ... down the hill" -- which was recovered from Libby's phone.
Authorities released a new suspect sketch in 2019 that officials said was based on a witness' recollection of what he or she saw.
The head of the Indiana State Police, Doug Carter, gave a direct message to the killer in an interview earlier this year with ABC News: "We know a lot about you ... today could be the day -- sleep well."
Police to announce update in mysterious Delphi double murder originally appeared on abcnews.go.com