Dr Bolster on Friday morning spent two hours examining Ms OâKeeffeâs body in the front seat of the badly burned car, which is registered to the suspect.
Ms OâKeeffeâs body was then moved to CUH, where Dr Bolster carried out a postmortem before making gardaà aware of her findings.
It is understood that Dr Bolster took a number of samples for further analysis to try to establish how exactly Ms OâKeeffe died.
Gardaà are hoping that these further tests, which will take a number of weeks to complete, will indicate whether Ms OâKeeffe was alive or dead when the car went on fire.