Sherrifs in Bedford County, Va., say there have been major developments in the disappearance of Katherine and Sheila Lyon.

On March, 1975, Katherine, 10, and Sheila Lyon, 12, disappeared from Wheaton Plaza Shopping Center in Maryland when they went to see an Easter exhibit and grab a slice of pizza from the mall, according to the Charley Project.

The day they disappeared, both were supposed to be home by 4 p.m. and their mother called authorities when they didn't return. A major search ensued, and despite authorities acquiring over 2,000 leads, none of them led to any physical evidence, according to CNN. 

The most promising lead came from a witness in Virgina, who reported seeing two girls resembling the victims, bound and gagged in the back of a station wagon. However, the police were unable to get the license plate number and were forced to consider the report "questionable".

Since last October, authorities have been looking at two men who are considered persons of interest in the case: Lloyd Welch and his uncle Richard, according to MyFox DC.

However the only actual charge brought up in relation to this case was against Richard Welsh's spouse when she was indicted on a felony perjury charge for lying to the grand jury.

Representatives of the Montgomery County State's Attorney's Office and police department, Bedford County Sheriff Mike Brown and Commonwealth Attorney Randy Krantz will hold a news conference today at noon.