Authorities are testing a hunk of concrete found in a Pennsylvania home that they hope will solve the mystery of a 1989 cold case involving a woman who vanished without a trace.

FOX News reports that Sunbury Police Chief Tim Miller announced that forensic experts are testing the concrete slab to determine if it holds any clues on the disappearance of Barbara Elizabeth Miller. Preliminary tests performed earlier month showed the concrete slab contained wood chips, and authorities speculated the victim may have dismembered by a wood chipper before being buried.

According to Miller, a forensic pathologist testing the concrete is currently “dissecting the walls, so to speak, piece by piece, hammer-and-chisel type, looking for the smallest of clues.” Authorities think Barbara may have been killed in 1989 by her former boyfriend and ex-cop, Mike Egan. Miller said that Egan has remained the primary person of interest since the victim’s disappearance. Egan, now 59, still maintains he had nothing to do with Barbara’s disappearance.

Court records indicate that throughout the years, Egan would make reference to visiting his “old lady” at the Milton home where the concrete slab was located. Egan’s sister, Cathy Reitenbach, lived in the home in 1989. Reitenbach, who died in January, was one of the last people who saw Barbara before her disappearance.

Egan served time in prison for receiving stolen property while he was still a police officer. He was paroled in 1988.

Barbara apparently complained about Egan to authorities in the months preceding her disappearance. Days before she vanished, she told friends she was scared for her life. Barbara’s then-teen son, Eddie Miller Jr., told detectives that Barbara and Egan were fighting on  June 30, 1989, over her plans to go to a friend’s wedding alone. Later that night, she disappeared. The morning after the friend’s wedding, Egan was reportedly driving Miller’s car when her son noticed yellow clay on the tires, indicative of possible concrete work.

Seventeen years after she disappeared, Barbara was pronounced dead, although authorities never found her body. The announcement brought a renewed interest in the case, and local news agency, Sunbury Daily Item, pressed Police Chief Miller to reopen the case.

In 2009, police received an unpursued tip about the Milton home. The tipster said Barbara was hidden inside the house. Earlier, in 2005, another tipster told police that Egan put Barbara’s remain inside the walls of the home, and would often get high on cocaine before driving by the home to check on “his old lady.”

The current homeowners allowed authorities to investigate the basement, where they found “highly suspicious” portions of cement that seemed to have been added on by hand. More than six cadaver dogs who were brought in to sniff out human remains hit on the same spot in the basement. Afterwards, authorities hauled off the chunk of cement for testing.

Investigators also found a metal barrel during a recent search of a pond near Barbara’s old home, but they’re keeping mum on what they discovered in the barrell.

Check back with CrimeOnline as additional details become available.

[Feature Photo: Handout]