Sergei's son felt that it was enough.
On the night they had agreed upon, Selev left the back gate unlocked.
He even checked the rooms and windows before midnight, in case Sergei's son broke in.
After everything was done, he drank some alcohol and soon fell asleep.
The next day, he discovered Sergei's son floating in the backyard pool, dead.
Naturally, Selev didn't dare reveal that he knew the person. As it so happened, snobbish Katie was unwilling to cooperate with the police, and the investigation didn't go smoothly. Hence, Selev was never exposed.
But that was all Selev would confess to.
He wasn't an idiot, and certainly wouldn't talk about how he had let Sergei in and helped the man drown Katie.
Elsa knew that Selev was a major suspect in Katie's murder, but she decided to interrogate him about that later after Sergei was arrested
