In any case I make it a point not be be fooled by the religious clothing of the fake Jews.
[There is a related issue here about "Semicha" which is no longer in existence. It stopped sometime in the middle of the time the Talmud was being written down. So the problem of fraud also exists in people that are "Torah Scholars that are demons" as Reb Nachman phrased it. In his major book it is mentioned in a side note that this idea comes from the Zohar, but in fact it was Reb Nachman that specifically noted the problem with supposed teachers of Torah. This problem is well known to the Na Nach groups that follow Reb Nachman's teachings as per Reb Israel Oddesor made a point to emphasize this aspect.]
The whole issue of legitimacy of authority got mixed up. In the Christian world they have ordination as an attempt to decipher. But in the Jewish world the stringent indication of counterfeit authority is ordination. This is because true ordination stopped during the Talmud period. And that kind of ordination is the only kind the Torah recognizes as valid. So what you have today is anyone claiming ordination is by definition a fraud.
To some degree this was recognized in authentic yeshivas where true Torah was learned like the Mir in NY. But even there a kind of blind eye was turned to people that went to get the false kind of ordination you have nowadays.
There is a such a thing as a true Torah scholar but that is more or less an unofficial position. That is a person that is recognized as knowing the Torah well and usually there is no doubt to who this applies.
The best thing is to refuse to ask questions or go to these false prophets of the Baal and to do with them like Elisha the true prophet of God did with the false prophets.