Complex sentence: Terry's first lead is to check on Tim Drake confirming that Tim has been under constant physical and psychological observation since his as the Joker.Terry then proceeds to confront and question Dick Grayson.
Split into simpler sentences: Terry's first lead is to check on Tim Drake confirming that Tim has been under constant physical and psychological observation since his as the Joker. Eliminating Drake as a possible culprit, Terry proceeds to confront and question Dick Grayson.