I stared at the screen, holding my breath, expecting to see betrayal… but instead I saw a nightmare.

Derrick was not kissing her. He suddenly threw the woman onto the bed — onto our bed — and his hands closed around her neck. At first, I thought it was some kind of rough game. But within seconds it became clear: it was not a game.

His fingers tightened more and more, his face twisted, and she desperately tried to break free.

I screamed in the empty car, as if he could hear me.

After a minute, her body went limp. He kept his hands on her neck for a few more seconds… then calmly stood up. Adjusted his shirt. Looked around. Lifted the lifeless body, carried it out of the house, and loaded it into the car.

I sat there, clutching my phone, unable to understand how this was possible. How could I have lived with this person? Slept beside him? Cooked him dinner? Said “I love you”?

I went to the police with the recording. He was arrested that very evening. But the real horror was still ahead: in the house they found an archive — dozens of recordings. It was not the first time.

He brought women over again and again. He strangled them. And he kept the videos because he took pleasure in watching them again.

I lived for seven years beside a serial killer… and never suspected a thing.