A local CVS worker has been arrested in the mysterious murders of two Indiana teen girls who were killed while hiking near their hometown five years ago, police confirmed Monday.

Richard Matthew Allen, 50, was arrested Friday on two murder counts in the 2017 slayings of Liberty German, 14, and Abigail Williams, 13, in Delphi in northern Indiana.

The bodies of the two girls were found in a rugged area near a hiking trail on Feb. 14, 2017 — one day after they vanished during a day off from school.

Their deaths were ruled a double homicide at the time, but authorities still haven’t revealed exactly how they were killed or what evidence they had in the case.

Allen’s arrest is the first major update in a years-long case that has haunted the small city of about 3,000 people.

“It’s concerning that he’s a local guy,” Carroll County Prosecutor Nicholas McLeland said during a news conference on Monday.

The evidence against Allen, who was working as a licensed pharmacy technician at the local CVS store prior to his arrest, has been temporarily sealed to avoid jeopardizing the “integrity” of their investigation, authorities said.

A judge found probable cause to arrest and hold Allen without bond, authorities said. Allen entered a not guilty plea at his initial hearing on Friday, McLeland said.

Libby’s grandmother, Becky Patty, told reporters on Monday that Allen had once processed photos for their family at the CVS but he didn’t charge them.

Posters seeking information about the murder of the teen girls were still hanging in the window of the CVS store where Allen worked on Monday.

The teen’s grandfather, Mike Patty, added that they always knew the suspect could have been “living right amongst us, hiding in plain sight.”

“That’s why we never stopped searching anywhere, because we didn’t know where he was,” Mike said.

Authorities insisted they haven’t “closed the door on the investigation” after being asked if they were looking at whether anyone else was involved in the murders.

State Police Superintendent Doug Carter said the probe is “far from complete” and urged members of the community to continue to come forward with information.

The girls were reported missing on Feb. 13, 2017, after they failed to return from a hike near the Monon High Bridge just outside their hometown.

The eighth-graders had documented some of their walk on Snapchat, and chilling grainy footage taken from Libby’s phone was released by cops early in the investigation that showed a man walking on a bridge near where the girls were last seen.

An audio recording was also released of a man, believed to be the suspect, saying “down the hill.”

Authorities previously hailed Libby as a hero for managing to record the potentially crucial evidence before she was murdered.

CVS issued a statement in the wake of Allen’s arrest, saying the company is “shocked and saddened to learn that one of our store employees was arrested as a suspect in these crimes. We stand ready to cooperate with the police investigation in any way we can.”

“We remain devastated by these murders and our hearts go out to the German and Williams families,” the statement continued.

With Post wires