Why did they need to use an identikit to reproduce Makishima's face?


I've been watching Psycho-Pass. Makishima has been working as an art professor
at a women academy. During an investigation, an audio clip is retrieved where
a girl (this particular case's culprit) speaks with him, mentioning his name.
So now the investigators know that there is some guy called Makishima within
the academy.

After a brief encounter between Tsunemori and Makishima, he escapes. Later,
Tsunemori uses an identikit to relive the experience to reproduce his face.
After the face is generated, they go to the academy and confirm that he was
indeed a professor there.

![enter image description here](https://i.stack.imgur.com/9aJLu.png)

To the left is the identikit image, and to the right what I imagine is the
academy's archive photo. They compare them (wow, powerful hairspray) and they
match.

But why an identikit? They **already** knew his name, so all they had to do
was go to the academy and mention his name. Then they show the archived photo
and Tsunemori would recognize it without having to relive the experience.




Actually Makishima didn't use his real name to register as a professor at Oso
Academy but use his alias "Yukimori Shibata". Only one who knew the truth in
the school is Rikako Oryo.

