Oooooo, this is a great topic idea! I used to be a mental health evaluator in the criminal justice system, so true crime elements in all media forms have a significant appeal to me. So many of the cases in LA Noire come to mind, the Phoenix Wright series, Batman: Arkham All the Things' use of detective mode and clue finding, those Sherlock Holmes adventure games (demon Watson notwithstanding), even the crime scene investigations from Heavy Rain...

Most memorable for me though is probably from Star Wars KOTOR - the Jedi investigation into a murder on the Selkath homeworld of Manaan. After landing on the planet, you get sucked into gathering evidence and weighing in on the legal proceedings of a Republic sympathizer who is accused of murdering a woman with known Sith connectioins in a dingy (as dingy as that era of graphics could allow) hotel room. Was it political manuevering, an assassination, a spat between lovers turned violent, or a freak accident? You get to collect evidence, interrogate witnesses, and use the Force however you see fit (okay, lots of mind manipulaiton) in the process, and during the trial, you can even withhold or falsify evidence to justify your ethical allegiance(s). I specifically remember this one because when I played through KOTOR for the first time, I was still in college waaaaaay back in 2003, trapped at home with my roommates during an ice storm. We played through the entire game over the course of a few days, and this came right after the big twist involving ********** - forced me to re-evaluate who is this character going to CHOOSE to be in the process of investigating the crime with the knowledge he now has of his identity. Good stuff!!!

My own murder in Ghost Trick: Phantom Detective!

Playing Nier Automata, I was tasked with finding the group of Androids that were causing problems for the resistance camps. After about 40 minutes of not finding any of them, I realized it's random when I will see them.

I find all three in three separate locations. Job done. I return to the the resistance camp only to be told that they weren't having any problems with anyone.

Well damn, okay. I guess case solved. I get a message from my operator to "be careful of others" and nothing else. Case solved?

My favorite Murder Mystery solving case was in LA Noire

I'd say that saving the world in Under a Killing Moon was quite a feat for the private detective Tex Murphy :P

A game that really changed my perspective on civilian surveillance was the first Orwell game, "Keep an eye on you."
In the game you play as an independent contractor that gets access to a new type of surveillance platform that gives you the ability to collect information on people via their social-media. Your task is to track down a random person seen on a surveillance camera when a bomb goes of in the middle of the city, potentially implicating them in the crime.

The staggering amount of information you get to collect on them, and any person they have any kind of link to is scary. It really shows what kind of sick reality we live in (because this game is not far from real life) where any organisation, be it government of other, can spy on its citizens in the pretense of protection. And the game shows a best case scenario, a terrorist bombing, where this kind of tec might be justified. It still feels wrong.

Orwell really changed my position on surveillance and I'm happy that I got to take part in the ideas i has to share. A must play in my opinion.

Many options have alreadfy been put, but here's my take.

3- The trial in Selkath in KOTOR

2- The Ace Attorney triology.

1 - Finding out the truth in Planescape Torment.

Many more options like the Return of Obra Dinn could be included, but reading this whole thread has already given me some ideas for the next games to play.

I mean the whole Septerra Core game was a big crime mistery solving game with awesome story and memorable heroes. Wish they made another part of that series ...

I really liked solving the murder of Captain Morales in Lionheart: Legacy of the Crusader. You can either fight and kill the ghost of the captain who was stabbed from behind or you can talk to him and he'll give you the quest to find his murderer.

You have to ask around the docks for someone and you learn from the new captain that her predecessor was a great captain etc but no clues. Then you find a sailor with his tongue cut off who seems to know something but can't say it. But he makes the gesture of horns on his head; so you go looking for a guy with horns.

In the tavern you find a Demokin (horned race in the game) sailor who'll try to pick ask you to leave if you haven't talked to the others before. But after doing the abovementioned stuff, he finally says the he and his tongue-less comrade saw a crew member stabbing the captain from behind on a rainy night but he was too afraid to reveal her identity because she might kill him too.

Being the only other ''she'' on the docks, you again go talk to the new captain who revels that she indeed killed captain Morales so she could better use the Spanish Armada to crush the English, which she was sure Morales couldn't / wouldn't do. She tells us that we won't stop her and not to get in her way and that if we do there'll be blood then vanishes and is forgotten for the rest of the game :P

You go back to the ghost on the Barcelona coast and give him closure, and as a reward, he shows you the location of some buried treasure before passing on.

Also, the GOG version of the game is the only version available with some special quests and overpowered items that make it much easier to do a mage build in the combat oriented game.

A 'Man in Policeman Uniform' case from Devil's Attorney, honestly.

Yes, it's not a pure 'investigation' since we're playing as an attorney, not as a detective.

(and the gameplay have nothing in common with investigations)

But hey, if the accused was acquitted - it means case closed, mystery solved, completely, yes?

And ingame newspaper headlines were plain hilarious next day.

The first case that crossed my mind was the one of vanished Number Nine tickets (thanks, Hector!) in Grim Fandango.

But then I remembered Her Story and its wonderfully written, intriguing story. I guess, that's my all time favourite crime case. When I think about it... I think, I should return to it once more :-)

The most memorable criminal case I ever solved was in Persona 4 Golden and when you had to go on a manhunt for an unidentified killer that loved using TVs as a form of murder.

The Witcher 3 - Carnal Sins

This quest had it all!

1. A surprise horrible attack on a popular character (Priscilla)

2. Comedic Relief (Examining the Dwarf's genitals)

3. Gruesome deaths (The Vegelbud Residence)

4. A 'Red Herring' Killer (Reverend Nathaniel)

5. Vampires! (Hubert)

I suspected him right away as he looked so much younger than the doctor who said that Hubert was his teacher but I loved the reveal regardless. You actually felt like a detective following leads and getting closer to the killer. I also love how players who are quick to judge or didn't think deeply enough about the situation can 'fail' the quest by getting the wrong man. One of several memorable side-quests in the game!

Solving the Voodoo murders in Gabriel Knight: Sins of the Fathers back in 1994. It made such an impression on me that I even traveled to New Orleans a few years later and visited the real life landmarks used in the game.

The most memorable instance of solving a criminal case within a video game for me seems to be the Vizima Confidential and its related quests in the second chapter of the first Witcher game. Witcher 1 has been my favourite entry in the series in some respects, though Witcher 3 overshadows it in many aspects.

The dark and gloomy neighbourhoods of Vizima provided excellent backdrop to the quest for unearthing the activities of Salamandra, and added a sense of mystery and intrigue. The level also felt very alive with numerous story characters and NPCs who enhanced the atmosphere. The investigation involved so many memorable characters. Also the many layers of intrigue surrounding the investigation, seemed to draw support from many layered spatiality of the city of Vizima and the narrative possibilities. And the fact that Geralt had to depend on not only his own ingenuity but also other people including his allies meant the detective work was weaved into a complex set of gameplay elements. The tussle of wit between Geralt and 'the impersonator' (I am not going to spoil the twist) lent greater interest to the climax of the episode.

This is my entry for the competition. Thanks to GOG and ZA/UM for organising it. Best of luck to everyone.