Mercy Peters, aged 41, originally from Sierra Leone, who had been living with Mr McKenna, aged 42, at his home in Marlay Court, Rathfarnham, south Co Dublin, has been charged with murdering him on July 17.
Mr McKenna and Ms Peters had been involved in running a publication for refugees. Mr McKenna’s body was discovered at his home by his father, Thomas, and an autopsy confirmed that he died from a stab wound.
Last Saturday, Ms Peters was remanded in custody by a Dublin District Court judge, who had made an order that she was to receive immediate medical and psychiatric attention.
Her case resumed yesterday but she could not come to court.
Detective Garda David Bunn told Judge Anthony Halpin at Dublin District Court that Ms Peters has been sent to the Central Mental Hospital, where she remains and is “still very unwell”.
Det Gda Bunn said it was not known how long the defendant will be at the CMH and he asked for a four-week adjournment.
Judge Halpin said that normally he would grant a two-week adjournment but, given the “extraordinary circumstances”, he agreed to the garda’s request.
The case resumes on August 21.