Gardai hunting for the murderer of the Dublin teenager, Ms Raonaid Murray, have taken DNA samples from 10 people as part of their investigation.
These are being analysed and cross-checked against DNA evidence on two cigarette butts found near the murder scene.
Ms Murray (17) was stabbed to death three weeks ago in a laneway near her Glenageary home. Four cigarette butts were found in the laneway. There was no DNA evidence on two of them, one was smoked by a man and the fourth had been smoked by a woman.