Antoine Michel, Noel Michel, Raymond Marlowe, Henry John Lockhart and Stan Paul Desjarlais are charged with one count each of sexual assault.
Last week, Justice Ted Richard rejected Marlowe's application to have his trial moved out of adult court.
Marlowe's attorney argued that his client was under 16 at the time of the offense and should not be tried as an adult. The judge ruled that, under the law at the time, Marlowe would have been tried in adult court.
The jury trial of the five accused is expected to last five days.