Question Regarding Vladislav Roslyakov's Explosives

There's not much information regarding Vlad's explosives, other than:

A). The main bomb was a nail bomb.

B). The nail bomb was ammonium nitrate based

C). Any smaller IEDs were made of thick cardboard, black powder, fuse, wood plug, and reinforced duct tape.

His nail bomb is really the only acknowledged in news articles, and even then there isn't much details other than that. This was mainly mentioned in the comment section of this post: [You must be registered and logged in to see this link.]

There's a mention of a page of an IC report about small IEDs, which is mentioned in that thread in the comment section, however the link doesn't work anymore. However the IC report fragment mentions that; "he [Roslyakov] made this type of bomb in 2017 experimenting with explosives."

I know he had an online presence, but I think it was at most a youtube channel about minecraft. However Roslyakov (According to the wikipedia of the shooting) "had hobbies that included weapons and video games. In 2015 he joined the college to study to become an electrician. In college he developed an interest in explosives and weapons..", now he was studying to become an electrician so I will assume he had knowledge on circuits, how to set up a timer as a detonator which makes sense nail bomb was in fact detonated using a timer. I don't know how far his interest in explosives was, if he was testing bombs in 2017 that is roughly around a whole year before the massacre he was reading into bombs. Was he in any chem forums? or did he do his research by himself?

I guess to summarize, my main question is: how much information is available about Roslyakov's explosives? Weather that be how he learned to make them, or where he did and how long he was in fact testing and correcting his methods.

First of all, I'll clarify.
The trouble is that the information about the Kerch massacre was in a MEGA cloud, which was created by anons from 2ch "Kerchethread", in 2021 this archive was deleted, and soon after Perm in the section of the site threads about massacres were banned. Later the telegram channel where some of the files were located was also deleted. The thing is that the archive of 2ch suffered an accident and all 90 percent of all media files are lost, so in public access there is no central archive of full information on the Kerch tragedy.

If I remember correctly Sometime in 2020 an anonymous person came to the thread who claimed that he was from that group of anonyms that bought CCTV footage and forensics of Roslyakov's corpse and that he had information about it, I don't remember if any evidence was published there.

As for the bomb, many believed that it was ammonal.

BAZA published some of the information from the investigators:

"There are six minutes left before the big break. Roslyakov stops, puts his backpack on the bollard and slips his hand into it. The FSB bomb technicians believe that at this moment he synchronizes the time on his phone with a slowdown timer. Vlad burned his laptop, but the melted and erased memory card was recovered. There were links to cheap Chinese timers for 250 rubles. Roslyakov set such a device for exactly ten minutes: Vlad had specially chosen the time so that the explosion would take place five minutes after the start of the big break, when there would be more people. With the bomb ticking, he calmly walks down the hall to the main entrance and sits on a bench


Investigator's comment: We found Internet links to buy a deceleration timer from him — this is a regular timer that is used in the kitchen. He studied well, he did catch on quick, and the skills acquired at the polytechnic helped him in part. He also always had a dad on hand who could advise on some things. He positioned the explosive device in such a way as to injure the children as much as possible. That is, he put it at the level of the middle part, at the level of the legs. Roslyakov couldn't put the backpack on the table because it would immediately attract attention. He hung it on a hook or placed it at the bottom.

Investigator's comment: Roslyakov's father worked as a turner at several local factories, he
could make and fix anything. Since childhood, he showed his son how to assemble homemade firecrackers. Vlad, coming to his father's garage, told him that he was fond of pyrotechnic products and even tried to boil explosives of low power. Shortly before the tragedy, he shared that he had managed to achieve a certain explosive power of a substance that he had experienced in a local quarry. Up to the point that the explosion destroyed the stone.

The bomb's power is at least one kilogram in TNT equivalent. Then the explosives experts will find the remains of the frying pan on which Roslyakov assembled the bomb, so that the energy of the explosion does not go down, but is directed to the sides. Vlad learned all these details from the Internet: on the same memory card, investigators will find a bunch of links to materials on ballistics, explosives, chemistry and physics.

Investigator's comment: Our experts have restored the whole world into which he has been immersed for the last two years: links, articles and videos, visits to sites about maniacs and serial killers. He collected all this horror on a flash card. That is, Vlad was absorbed in this topic related to explosive devices, the use of weapons, deaths, and shootings.

The bomb leaves a funnel in the concrete floor, it almost completely demolishes the left wall of the dining room and the glass entrance."

Once a tragedy happened, there was information that Roslyakov had brought several powerful bombs to the college, but this information turned out to be false, he had only one big bomb that went off in the canteen.

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