Baltimore City police began working the case, focusing on suspects in the Catholic Church. The Baltimore County police took over the case when Sr. Cathy's body was found two months after her disappearance.
According to reports, she was found with trauma to the head, possibly from a hammer. The discovery of her body barely made the news - the local papers were on strike at the time.
Because the alleged abuse of Fr. Maskell had not been reported to the archdiocese or the authorities in 1970, when Sr. Cathy's body was found, Fr. Maskell was not originally investigated as a suspect in the case.
Earlier this month, local media reported that the Baltimore County police exhumed Fr. Maskell's body to conduct DNA testing, ahead of the Netflix series that closely links him to Sr. Cathy's murder.
There were few others investigated as possible suspects when the case opened in 1969.
On the night of Nov. 7, 1969, when Sr. Cathy disappeared, she had driven to Catonsville to cash a check, and then went to a bakery in the Edmondson Village Shopping Center. When she didn't return after what was supposed to be a brief errand, concerned roommate Sr. Helen Phillips contacted Fr. Gerard Koob, a close friend and alleged romantic interest of Sr. Cathy.
Fr. Koob and a friend drove to the women's apartment, and after talking to Phillips and hearing nothing from Sr. Cathy, they contacted the authorities to report her as a missing person.
Koob, now a Methodist minister, was thoroughly questioned by authorities at the time. His story that he had been at the movies with a friend that evening before learning of Sr. Cathy's disappearance has held, and he has passed two lie detector tests regarding his whereabouts that night.
Lacking leads and new evidence, the case went cold around 1975, but was picked up again in 1992, after a woman named Jean Wehner came forward and reported that she had been abused at the hands of Fr. Maskell.
The archdiocese removed Fr. Maskell from ministry and sent him away for counseling and evaluation. Having no hard evidence against him, he returned to ministry in 1994.
At that time, Wehner revealed to police that Fr. Maskell had taken her to see Sr. Cathy's body to "show her what happened to people who crossed him," according to the Washington Post, and several other abuse victims came forward to accuse the priest.
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The Baltimore County police then questioned Fr. Maskell about the case, but he denied both the allegations of murder and of sexual abuse. He was permanently removed from ministry by the archdiocese in 1994, and he fled to Ireland in 1996 without the knowledge of the archdiocese.
The archdiocese has offered to each victim an apology and an opportunity to meet with the archbishop, and has offered to pay for counseling assistance for anyone who may have been abused by Fr. Maskell. Some victims have sought direct financial assistance through a voluntary, pastoral mediation program established by the archdiocese. To date, the archdiocese has provided over $97,000 in counseling assistance and over $472,000 in direct financial assistance to those who may have been abused by the priest.
"It became a healing process for a number of them," Sheldon Jacobs, an attorney for the victims, said of the settlements reached in 2016.
"Quite a few of them thought it was a cathartic experience," he told The Washington Post.
The archdiocese said that it was willing to provide comment and to answer questions for the producers of the new Netflix series about the case.
"Unfortunately, the producers asked very few questions of the Archdiocese before releasing the series and did not respond to the Archdiocese's request to receive an advanced copy of the series. Advanced copies were provided to media outlets," the archdiocese notes on its website.