The more common ways to say this are:

He is a policeman as much as he is a thief.

-OR-

He's a cop as much as he is a crook (or thief).

My First Question

He is a police as quickly as becoming a robber.
Can I use this sentence to express " he is also a police and robber"?

He is a corrupt policeman.

My First Question

He is a police as quickly as becoming a robber.
Can I use this sentence to express " he is also a police and robber"?

He is my colleague but sometimes he is my enemy.