A British nurse has been charged with murdering eight babies, as well as the attempted murders of 10 others, after a years-long investigation into an unexplained spike in baby deaths at a hospital’s neonatal unit.

It’s the third time that Lucy Letby, 30, has been arrested. She was previously detained in 2018 and 2019 as authorities probed the string of infant fatalities at the Countess of Chester Hospital in England. Both times, the nurse was released with no further action against her, but she appeared in court Thursday to finally face 18 formal charges.

In the courtroom, the nurse learned that she faces eight charges of “murder of a victim under 1 year old,” and each infant victim’s name was read aloud to her. According to BBC News, five baby boys and three girls died. They were named Cemlyn Bennett, Joseph Johnson, Barney Gee, Joseph Gelder, Eli Gelder, Elsie McNall, Daisy Parkin, and Maddie Freed.

Letby did not speak in court other than to confirm her identity, and her representatives have not said whether or not she plans to plead guilty. The media has been ordered not to report the names of the alleged victims of attempted murder, but there are reportedly five boys and five girls.

The charges all relate to a string of baby deaths, and non-fatal collapses, at the Countess of Chester Hospital near Liverpool in 2015 and 2016. According to a National Health Service report into the incidents, the hospital launched a probe after resident doctors became concerned about what was described as a “higher-than-usual number of neonatal deaths on the unit, several of them being apparently ‘unexplained’ and ‘unexpected.’”

The police became involved a year later. This week, the inquiry’s leader, Detective Chief Inspector Paul Hughes, said that Letby’s third arrest came after more than three years of investigative work by his team.

Susan Gilby, chief executive of the hospital where Letby is accused of committing the crimes, said in a statement that the major development was of “serious concern” and added that the trust that runs the hospital will be “fully supportive and respectful of the judicial processes.”

Neil Fern, who is representing some of the families in the legal case, told The Guardian, “The families are overwhelmed with the news and there is a mix of emotion. All the families now have hope that they can finally start to learn the truth of what happened in the first days of their children’s lives. We have been working with the families for many years on these cases, and they have had to live with the consequences for all that time.”

Letby is expected to make another court appearance on Friday.