Police have arrested a 23-year-old man in...
According to investigators, the suspect used a mixture of brandy and psychotropic pills to make his victims unconscious and then robbed them.
"The investigation has established that the 2-time convict killed 13 people and caused severe brain damage to other 12 victims," Tatyana Morozova, a spokesperson for the Moscow Region transport police, said on Wednesday.
Morozova said the deadly mixture used by the killer caused cerebral edema, suffocation and painful death, while those who survived suffered memory loss due to the lack of oxygen in the brain.
The suspect has been on a killing spree for three years after he was released from prison in 2007.
He used a standard scheme in his crimes - he would approach his victims with an offer of a drink to celebrate his son"s birth and would rob them of money and personal belongings, including ID papers, mobile phones, jewelry, and credit cards after they lapsed into unconsciousness.