Investigations case 5: Detective Badd turning himself in to the police as the last remaining member of the Yatagarasu. Especially painful as Gumshoe, who views Badd as a father figure, is the one who has to make the arrest.
Despite being a... you know, the killer in Case 2 and a member of of the smuggling ring, Cammy Meele, actually gets a minor one when she breaks down and starts explaining what happened, moments before the murder, in a terrified voice, peetering out in the end. As well as the image you got of her killing Hicks. There doesn't look to be any malice or hatred. It honestly looks like a spur-of-the-moment act made out of fear for her life. It can actually bring a little tear to your eye imagining it.
A single line in Investigations case 4 brought this troper from laughter to sorrowful weeping in a single instant. When Kay shows up at the confrontation with Gumshoe in the courtroom regarding the Swiss Roll, I was happy to see Kay again, so cute, defending Gumshoe. Then Edgeworth presents a Swiss Roll to her, namely the one she dropped earlier. "I was saving it for Daddy." Cue waterworks.
You forgot something. Also cue Edgeworth telling her to let it all out, because her father had just died. In the courtroom. Just like his had ten years earlier. *keening whine* I had to put the DS down for a minute...
Interestingly, the most tear-jerking moment this troper knows of that scene has not been mentioned.
Then again, that moment does quickly decend into a crowning moment of funny. Edgeworth, feeling sympathetic to her as mentioned above, goes to one knee and offers her a hankerchief. She runs forward for what we think if a hug...which is instead her deciding to blow her nose on his cravat. His face is priceless. Although bringing it all back into tearjerker mode, I felt so sad when Kay freely admits that Edgeworth and Gumshoe remind her of her dad and Detective Badd. There's something kinda tragic in that, I think.
An then there's the sheer devotion Edgeworth has to von Karma, blissfully unaware that his mentor was his father's killer. Damn you, Dramatic Irony!
Just that entire messed up family in general. This troper gets a bit misty-eyed thinking about how Edgeworth and Franziska really do care about each other deep down, but Manfred manipulates both of them. And I think Franziska was really hurt by her father's disregard for her compared to Miles.
Honestly, I think my heart broke a little when Franziska asked whether he'd watch her first trial too, and he was just like "Hmm, yes, I guess so, whatever, I don't really care, go away now."
He actually said he'd consider it, but the sprites used made it look like he was joking and actually would go to her first trial, not to mention every time she asked if she could do something, he said yes without hesitating. He also seemed proud when Edgeworth got his first trial. All of this is kind of sad if you think about it: sure, he was a villain, but he's a human too, but that more human side is often ignored.
Something this troper didn't realize until replaying case 4: Detective Badd was probably a lot more upset over Faraday's death than he let on. The game made it sound like he was almost a second father to Kay, so he and Faraday were probably something like Heterosexual Life-Partners. He's really quite a sad character, when you think about it.
Probably more of a Crowning Moment of Awesome, but this troper had to take a breather while playing through AAI Case 5 when Lang, despite finding out about Shih-na's identity and all she's done, still takes a FUCKING BULLET for her.
Badd: You idiot...! What were you thinking, jumping in front of my gun like that...?! What're you risking your life for?!
Lang: I'm sorry, Detective Badd, but no matter what sort of past she might've had... or even if she is a spy, it doesn't change the fact that she's my subordinate. And as long as she is, I can't allow any harm to come to her, not even from you!
Shih-na/Yew: You really are... an idiot... you know that...?
That entire section where you're cross-examining Shih-na because you think she's the murderer was pretty damn harsh to me simply because of Lang. He's a Father to His Men, and as such the idea that Shih-na might be a traitor must have been so hard on him. I almost cried when he practically begged her to prove them wrong when they're accusing her. And despite that, he still cared enough about her to take a bullet to the thigh (which is an area full of very important arteries, may I point out) for her.
His fully crying animation is... really depressing. Poor kid.
Likewise, Mikagami's "terrified for her son" animation. The fact that it shows up very sudenly during Logic Chess with her, and she's been pretty much The Stoic the entire rest of the game, makes it hit even harder.
From the same case, there's, surprisingly enough, the real killer's breakdown. The first half of it, at least. The second... not so much.