Back to the Future: The Game - 30th Anniversary Edition

This achievement occurs during Episode 5 - Outatime

After getting Emmett out of the Bathysphere from Doc will be above the stage with Emmett and Judge Brown will be below, do the following:
• Interact with Judge Brown.
• Dialog (Judge Brown): "Emmett's gone."
• Interact with Emmett.
• Dialog (Emmett): "He's got to give you a fair trial!"
• Interact with Judge Brown
• Dialog (Judge Brown): "He says you won't listen."
• Interact with Emmett.
• Dialog (Emmett): "He promised he'd listen to you."
• Interact with Judge Brown.
• Dialog (Judge Brown): "It's important to Emmett"
• Dialog (Judge Brown): "Emmett's not like other people."
• Dialog (Judge Brown): "It's important to the future!"
• Dialog (Judge Brown): "Yes"
• Dialog (Judge Brown): "Emmett's different from you. He needs freedom!"
• Dialog (Judge Brown): "Your father didn't understand you either?"
• Interact with Emmett.
• Dialog (Emmett): "He says you're like your mother."
• Dialog (Emmett): "What did you just say...?"
The achievement will pop once Marty leaves the Expo

Credit to T_l_M_B_0 of PST

Here’s a full 100% Walkthrough for Episode 5 hope it helps!