The earliest you can get this is in the first Traffic case 'The Driver's Seat', here are the answers to the interviews in this case
Nate Wilkey
Purpose at scene : Good Cop
Knowledge of Adrian Black : Good Cop
Contents of wallet: Bad Cop
Bloodstained pipe found: Good Cop
Margaret Black
Slaughterhouse Receipt: Good Cop
Photograph signed 'Nicole: Lie (use Concealed Message clue, this is found in the bedroom in her house, pick up picture and press A to further investigate it and you will get this clue to use in the interview)
Location of Adrian Black: Good Cop
Stenzel glasses case: Good Cop
Cavanagh's bar matchbook: Good Cop
Alibi for Mrs Black: Good Cop
Frank Morgan
Link to abandoned vehicle: Lie (use 'Receipt for live hog' found in the trunk of the car at the freight depot.)
Location of Adrian Black: Bad Cop