YOU SAID:

I decided to kill him then,then I probed his cat

INTO JAPANESE

私はそれから彼を殺すことにした、そして私は彼の猫を調べ

BACK INTO ENGLISH

I then decided to kill him, and I examined his cat

INTO JAPANESE

私はそれから彼を殺すことに決めた、そして私は彼の猫を調べた

BACK INTO ENGLISH

I then decided to kill him, and I examined his cat