Law enforcement personnel of Nevsky district of St. Petersburg are searching for a man who opened fire on a hooligan who accosted him.
As it became known to the correspondent of <the news service>, a young man of 21 was rushed to the Aleksandrovsky hospital from 72 Metallist Avenue with a gunshot wound to the head. Law enforcement officials have managed to discover that the victim and his friends were accosting people on the street.
According to the preliminary information, a man of middle age, who was also accosted by the young men, drew an Osa traumatic pistol, put it to the head of one them and with the words "You must not behave like this in a public place. You are disturbing the citizens' rest." shot him. After this, according to the victim's friends, the shooter calmly walked away humming a tune.
The investigation of the facts is continuing and criminal charges are being considered.

An "Osa traumatic pistol" is a four shot derringer that fires .60 caliber 179 grain steel cored rubber bullets. That's what the state allows for self defense over there.

I can't tell from the article whether this was self defense or not. "Accosted" in newspaperspeak can be many things. However, I do have to give the man massive props for the great line.