According to the investigation, on February 28, a man who worked as an auxiliary worker in a household attacked a 64-year-old pensioner with a knife in the garage, and then on his 63-year-old wife in the house.
He also killed their 41-year-old daughter-in-law and her five-year-old son, and, having stolen a large amount of money and valuables, fled the scene.
On the same day, a 14-year-old girl who was in class could not get through to her relatives at home and got in touch with her father, who was in another region.
He asked a neighbor to go home, and he, in turn, called the law enforcement agencies.
The detained 26-year-old man was taken to Nizhny Novgorod for interrogation.
It was established that his acquaintance helped him to hide - investigators also work with him.
Earlier it was reported that a family of four was found murdered in the Nizhny Novgorod region.
The prosecutor's office took control of the investigation of the case.