This one was pretty challenging. I had to take a break to “reset” my ears to make it out. I’m still not sure about the last sentence, I might have gotten it completely wrong.
What I hear
もう三度目か四度目でしょうか。
私の家を隅々まで探し続けた警官達は、又地下室に降りていきました。
私は顔色一つ変えず、そんな彼等を見つめていました。
私の心臓は丸で罪一度も侵した事もない
真っさらに人間のように落ち着け祓っていました。
What I understand
Was it third or fourth time already?
Police officers, searching my house down to every corner, went down to the cellar again.
I was watching them without batting an eyelid.
My heart was calm and pure like the one of a newborn child who’s never committed a sin.
Spoiler
I got confused by 顔色一つ変えず, idioms are always pure evil when learning a foreign language 