Police in a small Pennsylvania city hope that the painstaking examination of a concrete basement wall dug up in June will solve the disappearance and murder of a woman missing for more than 28 years.

Barbara Elizabeth Miller, 30, of Sunbury, was last seen June 30, 1989, after attending a friend's wedding. The Sunbury Daily Item reported that her estranged boyfriend, a former Sunbury police officer, reported her missing five days later.

An affidavit filed in the case stated that the former detective, Joseph Walter "Mike" Egan, "is and has been the lead suspect in this case since 1989," the Associated Press reported. Egan had denied responsibility for Miller's disappearance.

Sunbury police Chief Tim Miller, who has no relation to Barbara Miller, said last week that wood chips and other unexplained materials have been found in the chunk of concrete wall that they believe may hold the remains of Barbara Miller.

The chief told the newspaper that the chips, “as well as other discoveries … continue to confirm that we are definitely looking in the right place.”

He confirmed to the AP that there is speculation that a wood chipper may have been used to dispose of Barbara Miller's body, but that it was "mere speculation if a wood chipper was or wasn't used."

The Daily Item reported that one of the people examining the evidence in the case is renowned forensic scientist Dr. Henry Lee, who, the same year Barbara Miller disappeared, helped Newtown, Connecticut, investigators prove the murder of Helle Crafts, an airline stewardess who vanished in 1986.

Crafts' husband, airline pilot Richard Crafts, was convicted of murder in 1989 after Lee was able to prove that bone fragments, hair and other human tissue, including a fingernail and a tooth, found on the banks of a local river belonged to Helle Crafts. The New York Times reported that witnesses saw a man using a wood chipper on the bridge a day or two after Helle Crafts disappeared.

Credit card records also showed that Richard Crafts had rented a wood chipper. He was convicted in a second trial in November 1989 and sentenced to 50 years in prison.

Crafts’ first trial, which ended in a mistrial, took place in 1988, the year before Barbara Miller disappeared. Both trials received extensive publicity.

In Barbara Miller's disappearance, the investigation had gone cold until Tim Miller became police chief in January 2016 and decided to take a fresh look at the case. The Daily Item reported in July that after more than 30 new interviews and additional investigation, the chief obtained a search warrant for a property in nearby Milton.

The Milton property, owned by a local county judge at the time Barbara Miller vanished, included a duplex the judge rented out.

One of the judge's tenants was Egan's sister, Cathy Reitenbach, who died in January, the Daily Item reported.

The newspaper said that court documents filed to obtain the search warrant indicated that investigators had received tips that Barbara Miller was either buried somewhere on the Milton property or entombed in the basement wall. The dig resulted in dirt and tons of concrete, including that three-ton basement wall, becoming evidence in the case.

Chief Miller said that every general contractor he has consulted with on the case said there is no reason wood chips would be encased in a concrete wall.

"Everyone I spoke to said it is suspicious to have wood chips in cement," Miller told the Daily Item. "There is absolutely no logical reason for wood chips to be inside concrete."

During the week-long dig at the Milton property in June, eight cadaver dogs alerted detectives to the presence of human remains. The dogs did so both at the property and at the site where the evidence from the dig was being stored, the newspaper said.

Perhaps the last person to see Barbara Miller alive, besides her killer, was her 14-year-old son, Eddie Miller Jr. Now 42, Eddie Miller said in July that he saw his mother when she returned from the wedding she had attended.

He went to sleep and, when he awoke, she was gone.

Lori Wands, the bride in the wedding that night, told the Daily Item that Barbara Miller was supposed to go home to change her clothes and then drive to Milton to meet up with the wedding party. She never arrived.

"There is not a day that goes by that I don't wonder what happened to Barb," Wands told the newspaper. "It's too bad it took 28 years for someone to follow all the leads. I commend Chief Miller and the Sunbury Police Department, all those involved for not giving up and hopefully giving us all closure, and then Barb can rest in peace."