To stick/stand out like a sore thumb.
This sounds very much like the English idiom to stick out like a sore thumb.
From Cambridge English Dictionary:
If someone or something stands/sticks out like a sore thumb, everyone notices them because they are very different from the people or things around them
An example use from the recent news media:
Apart from me, the queue for the Scenic Railway roller coaster in Margate is composed of teens and young families. I don’t like his intonation but I can see his point. As a 37-year-old man, I stick out like a sore thumb.
The logic behind the idiom is hard to pin down for sure, but WiseGeek asserts that it's simply because a sore thumb is often held at a stiff awkward angle, making it very noticeable.
The first explanation is probably obvious to anyone who has ever injured a limb. When an injury is sustained, the natural instinct is to protect the affected limb, and as a result, a sore thumb is often held at a stiff, odd angle that may be obvious to even the casual observer.
To be damaged goods
Another possibility that fits with the example provided and the notion of having a tarnished reputation would be damaged goods.
- A person whose reputation has been damaged, corrupted, or tarnished. The young CEO became damaged goods after news of his insider trading spread—now he can't even get a job flipping burgers.
This idiom and the example provided by Farlex fits well with the description provided in your example:
We use this idiom when we want to say that the person has done some works that have made him or his known. He or she has betrayed himself or herself.
You could say:
We can not trust him. He is damaged goods and may be arrested.