Phoenix Wright: Ace Attorney Trilogy

Story related, cannot be missed. You obtain this by completing the 3rd episode of Phoenix Wright: Ace Attorney. Check the walkthrough for a good guide.

Case 3 - Turnabout Samurai: spoiler-free walkthrough
Phoenix Wright: Ace Attorney continues with its 3rd case. Our walkthrough will help you solve this case featuring the Steel Samurai.

With one trail on his own under his belt, Wright undertakes a case involving the famous Steel Samurai...
Case 3, Turnabout Samurai: Day One Investigation

Here's the steps to take to gather all the evidence you'll need for trial - at least for now.

Go to the Detention Center. Talk to Will Powers.
Head to The Studio. Speak to Wendy Oldbag and exhaust your options.
Head back to the Detention Center. Ask Will Powers about Oldbag, the security lady, to get Powers' Letter.
Now head back to The Studio and present Oldbag with Powers' Letter. You'll also get the Guidemap item.
Within the newly unlocked Studio One area you'll encounter Gumshoe. Chat to him to get Jack Hammer's Autopsy Report. Keep chatting to him.
In the Studio One area, examine the following: the camera, the door and the mascot head.
Once that's done, head back to the Main Gate and chat to Oldbag about everything.
Head to the Employee Area. In there, examine the Lunch Plate, then scroll left and examine the Open Grate.
Go to Will's Dressing Room. Examine Will's bag to get the Cardkey item in your court record.
To use the keycard, return to Studio One and examine the door again to open it.
Inside Studio One, examine the cameras. You'll meet Penny. Discuss everything with her.
Back at the Main Gate, chat to Oldbag again. You'll have a new option that will make her leave in a huff.
With Oldbag out of the way, examine the computer. Choose ST1-307, which you learned earlier, to get Powers' Photo evidence.

Case 3, Turnabout Samurai Day Two: Trial

Before you even get to the trial in earnest, Gumshoe will once again fill you in on the investigation - you'll get the Samurai Spear added to the court record. Once the trial starts, quickly you'll be able to cross-examine Oldbag.

Oldbag's Testimony: Witness Cross-Examination

Present Powers' Photo on the 7th or 8th statement.

The Man in the Photo: Witness Cross-Examination

Press Oldbag on her 4th statement. This will cause a Court Record update.
Now press the 2nd or 3rd statement, then cycle through the statements.
Object to Edgeworth.

Oldbag's Testimony Continued: Witness Cross-Examination

Present Powers' Photo on the 2nd, 3rd or 4th statement.

The Other Person: Witness Cross-Examination

Press Oldbag on the 4th statement. There will now be a recess.

After Recess:

After the recess, choose The Security Lady (Oldbag)
Press Further when given the option.
When prompted, present either the Samurai Spear or Cardkey evidence. It's time for more testimony.

My Lips Were Sealed: Witness Cross-Examination

Press Oldbag on her 2nd or 5th statement.
When asked if you want to take a break, do so. It's time for more investigation.

Case 3, Turnabout Samurai: Day Two Investigation

You begin in the Detention Center. Talk to Will Powers.
Head to the Employee Area of the Studios. Penny is here, but leaves. Once she does, choose to Rip Open the newly covered grate. Then leave. Vandal!
At the Main Gate, chat to Penny for more information.
Go back to the Employee Area and then the Dressing Room. Meet Sal Menella. Chat to this curious fella.
Finally, now go to Studio Two. Examine the plates, the trailer door, the signpost, studio van, incinerator and flowerbed.
Head back to the Main Gate. Oldbag is back. She has nothing to say of worth.
Now head back to the Employee Area. There's a new person here - Cody Hackins. Talk to him.
After talking to Cody, you'll get an Empty Bottle. Examine it to update its description.
Back at the Main Gate, examine the abandoned guard station to get the Trailer Key.
Go back to Studio Two - this time you can examine and open the trailer door.
Move into the Studio Two Trailer. You'll meet Dee Vasques, the producer of Steel Samurai. Talk to her. You'll get Vasquez's Memo, which is meant for Sal.
Go back to the Dressing Room and present Sal with Vasquez's Memo.
Sal isn't helpful, so go back to Studio One. Inside, examine the director's chair. You'll get the Script item in your court record.
Back to the Studio Two Trailer - now show Vasquez the Script. She'll now talk about some interesting topics. You'll get Mr. Monkey's Head as evidence.
It's time to go back to the Wright & Co. Law Offices. Story shenanigans ensue.
Head back to the Studio Main Gate and chat to Oldbag.
Once you have, present Oldbag with the Cardkey. When given the option, Lend her the cardkey. You'll get the Steel Samurai Card in return.
Go back to the Dressing Room to meet up with Cody again. Present the Steel Samurai Card.
Go to the Studio Two Trailer and talk to Penny again. Once you've exhausted topics, present the Steel Samurai Card to her. You'll get the URP Card.
Back and forth - back to the Dressing Room, present Cody with the URP Card.
Finally, talk to Cody about all topics. When asked about Steel Samurai, choose His Fighting Skills. You'll get the Path to Glory in your court record.
When asked, you should say I Believe.

Case 3, Turnabout Samurai Trial: Day Three

Manella's Testimony - The Day of the Murder: Witness Cross-Examination

Here we go. Press the 5th statement. When asked, say "It's contradictory".
The statement changes; press the seventh statement.
When given the option, press harder.

Manella's Testimony - The Break: Witness Cross-Examination

Press Manella's 1st statement, then his 3rd statement.
When asked by the judge, comment "No, it's impossible."
You'll have a short recess, and you'll get Cody's Camera in the court record.

Cody's Testimony: Witness Cross-Examination

Cody takes a while to go wrong. Present Cody's Camera against statement 9.

Cody's Testimony - What I Saw: Witness Cross-Examination

Press Cody's 4th statement. When given the option, press him harder.
When asked, present Cody's Camera.

Cody's Testimony - No Photo: Witness Cross-Examination

Press Cody's 5th and final statement. Press him harder when asked.
When he revises that statement, present Path to Glory.

Things are taking a turn now.

When the judge asks, explain The Steel Samurai didn't win, then The Steel Samurai was the Victim
When given the chance, look at Cody's Photo and point to the "2" in the photo. Present that.
Now point to Studio Two in the Guidemap. Tell the court that The Trailer was there.
Edgeworth wants proof. Tell him you have it. Then present the Empty Bottle.
When asked, say Fingerprint the Bottle. You've bought time - and gained momentum.

Case 3, Turnabout Samurai: Day Three Investigation

You begin in the Detention Center. Talk to Will Powers once again. No groundbreaking info here, but there's some useful bits of context.
Head to the Main Gate and speak to Oldbag again.
Now go to the Employee Area. Gumshoie is here. Chat to him to get the Steak Plate evidence.
Speak to Gumshoe more. When you chat about Edgeworth, you'll get the Sleeping Pill Bottle as evidence.
Now how to the Dressing Room. Penny is here. Chat to her, and then when the topics are exhausted present her with the Path to Glory.
Return to the Main Gate and chat to Oldbag again. There's a new topic. When you can, say I Have Proof.
Provide that proof - present the Steak Plate to Oldbag, then the Sleeping Pill Bottle. She'll give you the Five Year Old Photo evidence.
Go back to Outside Studio Two and you'll see Vasquez. Present the Five Year Old Photo. Follow Vasquez, and see what unfolds...

Case 3, Turnabout Samurai Trial: Day Four

Vasquez's Testimony - The Day of the Murder: Witness Cross-Examination

Vasquez takes the stand, then. As part of the testimony, Van will be added to the court record.
Present the Steak Plate on the 6th statement. When asked, say "You Didn't Eat the Steak".
When asked, choose "Meeting the Steel Samurai"
When asked, say "You couldn't, could you?"
Present the Samurai Spear as evidence when prompted.
When asked by the judge, say "I can tell you", then present the Five Year Old Photo.
Next, say "She Had Another Way" and then present that new evidence, the Van.
When asked a question by Edgeworth, say Of Course He Has.

Vasquez's Testimony - After Finding the Body: Witness Cross-Examination

Here we go. This is it. Press Vasquez on her 6th statement. Press harder when asked.
Once her final statement changes, present Powers' Photo to her. Then tell her "You Saw Hammer Limping".
Select Of course I can prove it - and then once again present the Five Year Old Photo.
When asked, select Reveal Evidence - and then "She Had No Motive".

After this, the truth will be revealed. When speaking to Will after the trial, present him with Powers' Photo.

Not my guide, thanks to rpgsite.net