There is an episode of Conan about a woman in a black dress waiting for someone, who is later found

You're talking about Conan's 575 alibi for the black dress.

575 Alibi for Black Dresses (Part I).

576 Alibi for Black Dresses (Part II).

The victim robbed the murderer's boyfriend, and the killer killed her in revenge.

The two people each have the same gothic loli dress, and the murderer appears in a coffee shop disguised as a victim in a dress, pretends to go to the toilet, and changes his clothes to come back and wait for someone.

Those two episodes are:

576 Alibi of the Black Dress (Part II).

575 Alibi for Black Dress (Part I).

You haven't finished reading it yet, so I'll give you an address to read it

It's a gothic loli.,That episode is boring.。