18-year-old Vladislav Roslyakov captured here on CCTV buying shotgun shells.
150 according to Russian Media.
Four days later, he committed a massacre.
Shooting fellow students at a college in the Crimean city of Kerch.
The Russian Health Ministry says at least 21 people died.
Most of the victims were teenagers.
A teacher described seeing children's bodies everywhere.
Witnesses also described a large explosion in the school cafeteria.
The head of the Russian-backed administration in Crimea says the gunman - who then killed himself - acted alone.
(SOUNDBITE) (Russian) SERGEI AKSYONOV, HEAD OF THE RUSSIAN-BACKED ADMINISTRATION IN CRIMEA, SAYING: "Most important is to find out the reasons.
What pushed this inhuman (person) to commit this crime?
We don't understand that yet … He always behaved himself, he was very calm.
He never caused any trouble." Outside a Kerch hospital on Wednesday (October 17) night, families desperate to hear if their loved ones were safe.
Here a hospital worker saying four people in intensive care haven't been identified.
She's asked - are they boys or girls?
At the site of the attack - a church service.
Alongside the candles and flowers laid in memory, there's a strong army presence in the city.
Kerch and the rest of Crimea was annexed by Russia from Ukraine four years ago, leading to Western sanctions and international condemnation.
President Putin has called for a careful investigation into the shooting, which authorities say isn't terrorism-related.