Ms Blackmoore was 10-weeks pregnant when she was stabbed to death 17 times in her Wainoni home in August 1995. She was 21.
Two people, a 47-year-old woman and 45-year-old man, have been charged with her murder.
Both were granted interim name suppression when they appeared at the Christchurch High Court on Thursday morning. The public gallery was full for the appearance.
The man appeared by audio visual link and the woman appeared in person. Both were remanded in custody but have made applications for electronically monitored bail.
The woman entered a plea of not guilty and the man did not enter a plea.
He will be required to enter a plea by December 13.
Suppression applications will be argued on December 5.