Simplify the following text for a Grade 11 native English-speaking person.
Original: Armenians hoped Yanikian 's trial would provide a vehicle for proving the massacres in a court of law , while there were still surviving witnesses but the District Attorney did n't agree .
Simplified: Armenians hoped Yanikian 's trial would provide a vehicle for proving the massacres in a court of law , while there were still surviving witnesses .