Wakita's bending his legs and stooping, especially throughout the first chapter, where it would be easiest to get his height.
However, he stops at one point before going back to it.
I decided to mark things up to figure out the guy's height and he's taller than Kogoro, based on belt placement and hand placement at rest compared to Conan.
Interestingly, using the pickpocketing victim, we know she's shorter than Ran.
And Ran's relative height to Kogoro.
However, we do get a slight comparison between one of the taller suspects and Wakita, based on the door.
Victim vs Door, the top of the sign's at her height.
Wakita vs Door requires some maneuvering due to the odd angle, but he's taller than the top of the sign.
This is also confirmed by Wakita and the suspect being about the same height.