Is there any equivalent for this Persian idiom: "Like a cow with a white forehead"?
He may be a marked man:
A man who is singled out as a target for hostility or attack. 'he said what they did was wrong and he may well be a marked man now'
Source: Oxford
Or maybe he just sticks out like a sore thumb:
phrase. If you say that someone or something sticks out like a sore thumb or stands out like a sore thumb, you are emphasizing that they are very noticeable, usually because they are unusual or inappropriate.
Source: Collins
From the above definition, noticeable might work, since it isn't overtly negative:
easily seen or noticed; clear or apparent.
Source: Oxford
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 Washington Post
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.
- Farlex Idioms
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.
You could describe the person as being conspicuous:
standing out so as to be clearly visible.
"he was very thin, with a conspicuous Adam's apple"
attracting notice or attention.
"he showed conspicuous bravery"
"We can not rely on him. He is conspicuous and may be arrested."
"X has a target on [his/her] back" works for your example.
Some samples from search:
De'Aaron Fox says Lonzo Ball has a 'target on his back' from NBA players(sports)
Reince Priebus May Have A Target On His Back (USA politics)
From your comment.
when one of your members become known to people ,especially police ,you can not be sure to assign a work to him or her anymore. He or she is not necessarily a person with bad fame . perhaps he is even for them a hero .
If so it kind of sounds like "Burned" or "Compromised." These meanings come from espionage terms. Not sure if they're actually used by real spies, but they were used a lot in spy novels and movies.
It means that the person involved is no long useful against a particular group or in a location because they are now well known by them.
Burned tends to mean that the action that made them known was intentional and controlled. For example an undercover police officer will have to become known if he arrests a bunch of criminals. (see the example below)
Compromised tends to indicate it wasn't intentional and also indicates the person might be in immediate danger. For example the police might find out the identity of one of your members, and the member works at the police station feeding information to other members. Well he's suddenly in immense danger now.
A full example: In the U.S. a police officer might pretend to be a drug dealer in order to infiltrate a drug organization. Once the officer gathers enough evidence he'll call in other officers and they'll arrest the leaders of the organization. Afterwards, the police officer gets a medal and ends up all over the news. He's now "burned" as an undercover police officer since anyone that saw that news broadcast will instantly know he's a police officer.
Is that closer to what you meant?