Who is Ruslan Boshirov?Throw or puncture intelligence?

According to journalists, one of the suspects in Skripale’s poisoning is the GRU Colonel Anatoly Chepiga. How did they find it out and is it possible to believe this information?

Teresa May accused Russia of gross violation of international law. “From the seizure of sovereign territories to the reckless use of chemical weapons on the streets of Great Britain by agents of the Russian GRU,” the British Prime Minister said at the 73rd session of the UN General Assembly. Earlier on Wednesday, a group of Bellingcat and The Insider reported that they were able to identify one of Skrypaley, who was suspected of being poisoned.

Investigators claim that they were looking for Bashirov among graduates of Russian military schools who are suitable for age. They found a similar person on the site of the Far Eastern Higher All-Arms Command School, in a picture of his cadets in Chechnya. Seven graduates of the school, as follows from the caption to the photo, received the title of Hero of Russia.

Why the investigators decided that a person similar to Boshirova also bears this title is not clear. But they decided to look for a suitable Hero of Russia by age - and found it. This, as stated in the publication, the Colonel of the GRU Anatoly Chepiga. The fact that we managed to find out about this man, says the editor-in-chief of The Insider Roman Dobrokhotov:

As evidence that Boshirov is actually Colonel Chepiga, three photos are cited. Two pictures - from the passports of Chapigi 2003 and 2009, obtained from some sources. The third unveiled the British police, on it - Ruslan Boshirov

There are certain similarities between all three images, but I would not categorically state that the same person is depicted in them. However, those who wish can look at the photo themselves and decide whether Chepig looks like Boshirova.
The name of Chepiga is in one of the bases (which one is not specified), where his residence address in Khabarovsk in 2003-2005 coincided with the address of the military unit corresponding to the 14th GRU special forces brigade. Then the journalists found an extract from the Russian Passport system in 2014 with another photo of Chepiga. Regular users can use this system to check by passport number whether it is valid or not. True, there is a possibility that unauthorized access could be obtained to a closed part of the system.
All veterans of the special services claim that neither photos nor data of agents can be found in any publicly available database. And even more so just on the Internet. This information is available only to personnel officers of the special services themselves. Among them, by the way, there are traitors. At one time, Sergey Skripal was the head of the GRU personnel department.