The former lead investigator in the Morgan Harrington homicide case released an open letter Tuesday, asking "the person with information" to provide it.

Harrington, a 20-year-old Virginia Tech student, left a Metallica concert at the University of Virginia on Oct. 17, 2009 and disappeared, authorities said. Her remains were discovered in January 2010 in a field on an Albemarle County farm.

In the letter, retired Virginia State Police Lt. Joe Rader asks whoever has information on Harrington's death to "do the right thing."

"It is time for YOU to stand up in the name of humanity and justice," he wrote. "It is time for YOU to show that you have a sympathetic and dignified place in your heart so heavily troubled, regardless of your involvement in the circumstances leading to Morgan's death."

The full text of the letter can be found here.

Anyone with information about the case can call Virginia State Police at 434-414-4456 or the FBI at 800-634-4097.