WILMINGTON, Del. (AP) — A Delaware man who pleaded guilty but mentally ill in the fatal stabbing a psychiatrist who once treated him was sentenced Friday to life in prison.

Christopher Frick apologized for killing 55-year-old Caroline Ekong, saying he wishes he could take it back, The Wilmington News-Journal reported.

“I wish everyone affected the best,” Frick said.

Ekong was found dead in her home in October 2015 shortly before Frick called 911 from his parents’ home to report that he had killed her. Authorities have said that Frick became angry after Ekong refused to let him leave a psychiatric facility and plotted her death for at least a year.

Judge Ferris W. Wharton sentenced Frick to life in prison plus 25 years. Frick’s plea means he will receive psychiatric treatment while incarcerated, either at the state psychiatric center or at a maximum security prison.

Ekong’s daughter, Koko Ekong, said during the sentencing that she has had sleepless nights and anxiety after discovering her mother’s body. She described her mother as a “woman of integrity.”

“She was a wife, a daughter, a sister, an aunt, a friend, a godmother, a stepmother, a colleague and a great medical practitioner. Most importantly to me and my brother, she was and is our mother,” she said.

Three mental health experts concluded in separate reports that Frick suffers from a host of mental disorders, including autism spectrum disorder, psychosis, schizophrenia and obsessive-compulsive disorder.

Public defender Kathryn Van Amerongen said at Frick’s plea hearing in September that the man, who began seeing doctors at age 4 or 5, was hearing voices in his head “mocking him for not having the nerve to kill her.”

Van Amerongen said Friday that his mental health has improved at the Delaware Psychiatric Center, where he has spent most of his time since his arrest.

“Chris is a good person, but very mentally ill,” his mother, Cynthia Frick said Friday. “We know Christopher is very sorry,” she said.

Superior Court Judge Ferris Wharton nevertheless found that Frick, who graduated with honors from high school and studied physics at the University of Delaware, was competent to enter a guilty plea.

Copyright 2024 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Join our Newsletter for the latest news right to your inbox