As said in many comments, giving suspects more to say in response to certain queries and a few more subtle hints/better verbs to the harder places to find would've been great.
Played this on another site...freaking mind boggling! You will probably play 3-4 times before figuring out the twist. Then probably 3-4 more times to solve it. This is such an thrilling and challenging narrative. Love this game.
nice story. Kind of anti-climactic though. Maybe a follow through with meeting aunt and mother and giving them the items they were looking for and telling them what you found, would tie up the loose ends better.