"The investigator of the Investigation Department in the city of Mytishchi ... detained a 45-year-old local resident suspected of murdering a man and a woman," the report says.
According to the investigation, on May 3, a company of four drank alcoholic beverages.
At some point, a conflict arose between the suspect and his acquaintance, during which he inflicted two stab wounds on the victim in the chest area.
"The suspect also inflicted about five stab wounds to the man who intervened for the victim, as a result of which the man died at the scene," the UK added.
As specified, the woman was taken to a local hospital, where, despite the assistance provided, she died.
Earlier in St. Petersburg, investigators opened a criminal case into the attack of a man with a knife on two people.