Blake Leggette, 26, and his 28-year-old girlfriend Victoria Henneberry were charged with first-degree murder two weeks after Saunders disappeared from her Halifax apartment in February.
Leggette and Henneberry appeared in Halifax provincial court separated by sheriffs in front of a large public gallery as proceedings got underway.
Senior Crown attorney Christine Driscoll said outside the court she expects to call 15 police and civilian witnesses to testify.
"We have a realistic prospect of conviction and we intend on prosecuting these individuals with the evidence that we have," Driscoll said when asked if she believes the case will proceed to trial.
"If, at any point, defence has anything they want to bring and talk to us about, then we're always open to discuss things with them.
"Our job is always to seek justice and if at any point we're able to do that in a way other than having a four- to six-week trial, we would do that."
Saunders' body was found in a wooded area off the Trans-Canada Highway in New Brunswick. The Labrador Inuit woman, 26, was a student at Saint Mary's University in Halifax who focused her studies on missing and murdered aboriginal women.
Five days have been set aside for the preliminary hearing.
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