Graham Dwyer is to be sentenced to life imprisonment later today for stabbing to death Dublin childcare worker Elaine O'Hara.

The Cork born architect with an address at Kerrymount Close, Foxrock was convicted of her murder last month.

Murder carries a mandatory life term so that's the only option open to Mr Justice Tony Hunt at Graham Dwyer's sentencing this afternoon.

But today's hearing serves another purpose, it gives Elaine O'Hara's family an opportunity to relate the impact her horrific death has had on their lives.

The jury heard evidence the 36 year old childcare worker was engaged in a predatory BDSM relationship with the architect who stabbed her to death at Killakee mountain in 2012 for sexual gratification.

As a remand prisoner 42 year old Dwyer has been held at Cloverhill Prison up until now.

A life sentence means he will be eligible for release after 7 years but on average a lifer these days serves 18 years and some serve many more.