Editor's Note: This is the fourth in a six-part series highlighting missing persons cases in Centre County.

Jennifer Cahill-Shadle is the most recent person with links to our area to suddenly vanish but she's far from the only one.

Cahill-Shadle, 48, was last seen May 15 at Walmart on North Atherton Street in Ferguson Township. She joins a group of missing persons connected to Centre County, including Joey Lynn Offutt, Ray Gricar, Hyun Jong "Cindy" Song, Dawn Marie Miller and Brenda Louise Condon.

Each one of these cases remains a mystery.

It's possible that State College residents could have information that could help crack one of these high-profile cases.

This is the story of Hyun Jong "Cindy" Song.

Song, an international Penn State student from South Korea, went to a Halloween party Nov. 1, 2001 at Player's Nite Club in the 100 block of West College Avenue. Later she went to a friend's house.

About 4 a.m., a friend dropped Song off outside of her home at State College Park Apartments in the 300 block of West Clinton Avenue.

Song's friends reported her missing Nov. 4. Many of her personal belongings were found inside her apartment, including her backpack, cell phone and purse.

At one point, a witness claimed Song could be a victim of accused murderer Hugo Selenski in Luzerne County. In January, a grand jury presentment, related to Selenski's perjury and witness intimidation charges, revealed authorities located roughly 12 destroyed bodies at his home. That investigation is ongoing and there's a gag order in the case.

Meanwhile, Ferguson Township police continue to lead the investigation into Song's disappearance with Detective Jonathan Mayer in charge.

Ferguson Township Police Chief Diane Conrad says the investigation is ongoing and that Song's DNA is part of various national law enforcement databases.

"The cases are never closed. If anything new comes along technologically or we get any new tips or any other information that comes to us that we think would tie into that case we would go ahead and look at that. It's not closed," Conrad says.

In 2013, with the assistance of the FBI, authorities obtained a DNA sample from Song's biological parents. Those samples are now part of national databases for missing persons and unidentified remains. Authorities say there is now larger potential to find a match.

Anyone with information regarding the whereabouts of Cindy Song can contact Ferguson Township Police at 814-237-1172.

Related Stories:

Vanished: Authorities Investigate Unexplained Disappearances in Centre County

Vanished: The Story of Joey Lynn Offutt

Vanished: The Story of Ray Frank Gricar