David S. McKeever, charged with fatally stabbing his longtime companion, Delma Murphy, in their New London home in November 2015, will likely use an insanity defense when he goes on trial in New London Superior Court in September before a three-judge panel.

McKeever, 50, has a history of mental illness and is hearing- and sight-impaired because he was born with a congenital disorder known as Usher Syndrome, according to court documents and testimony.

He had lived with Murphy, 46, for 11 years and referred to her as his wife when, police said, he stabbed her multiple times, wrapped her body in towels and a blanket and left her in a bedroom for several days. A friend concerned for her welfare went to the home at 53 Cole St. on Nov. 18, 2015, and found her body.

He initially was represented by attorney M. Fred DeCaprio, who announced to the court a year ago that McKeever would be pleading not guilty by reason of insanity and had opted to be tried by a panel of judges rather than a jury. In August 2017, McKeever wrote to Judge Hillary B. Strackbein to say he felt bullied by DeCaprio.

Strackbein appointed a new attorney, Christopher Duby, to the case at the request of both McKeever and DeCaprio. Based on information Duby provided to the court Monday, it appears McKeever has now agreed to use the insanity defense. He would be committed to the Whiting Forensic Division of Conneticut Valley Hospital if the court finds him not guilty by reason of insanity.

Relatives of the victim have been attending all of McKeever's court appearances and meeting with prosecutor Lawrence J. Tytla and Victim Advocate Stephanie Barber.

McKeever's next court date is Aug. 13.

k.florin@theday.com