For MOST of the cases, I've been going around asking the townspeople for clues first and then interview the suspects (i.e. if one of the townspeople tells me that one of my suspects know something, I only ask for their alibis and anyone who wasn't named, I ask for motives and alibis). However, have there ever been cases where someone kills the suspect before you interview them?
Plus, for the harder level cases, you will want to save your questions for asking them about alibis and evidence. I only ask them if they know anything AFTER I've asked them about alibis & evidence, and if I have questions left with them.