Kassidi Lally dated Karlie for one to three months when she was about 17 or 18 years old and living in Alice Springs.
Mr Lally said the last time he saw Karlie she was pregnant at a bus stop in Alice Springs.
He said his attention was first drawn to the tragedy by his current girlfriend who had been following the case of the "baby in the suitcase".
"She has been going on about it for a while, and then yesterday, when I got home from work she said,
'the mother's from Alice Springs. Do you know her?'," Mr Lally said.
"
She said the name and I didn't recognise the name. She showed me a photo and for about five to 10 minutes later, I was gutted. I was in complete shock. I didn't say anything. I couldn't really put a sentence together or anything."
http://www.abc.net.au/news/2015-10-...ied-in-karlie-pearce-stevenson-murder/6878164
Her ex boyfriend did not recognise the name.
Had she used another name previously?