He said the family was grateful for the support they had received from the police, Victim Support, friends and extended family.
"This has been a tragedy for all concerned but today's guilty plea will enable us to at last move forward with putting our lives back together, as much as we can. The family would now appreciate some privacy as we attempt to do so.''
Ms Taufale had a bachelor of applied science in psychology, and had worked with disabled men and women, disadvantaged youths and victims of domestic violence.
She had volunteered at Women's Refuge, and in the past two years taken up a job at Industrial Research where she worked as a science support coordinator.
Smith was remanded in custody and would be sentenced next month.
