YOU SAID:

I once killed a man who was in the park for the day and he looks like he has been there since the beginning of time

INTO JAPANESE

私はその日その公園にいた男を一度殺しました

BACK INTO ENGLISH

I killed a man once in that park that day

INTO JAPANESE

あの日その公園で一人殺した

BACK INTO ENGLISH

I killed one in that park that day

INTO JAPANESE

あの日その公園で殺した

BACK INTO ENGLISH

I killed him in that park that day

INTO JAPANESE

その日その公園で彼を殺した

BACK INTO ENGLISH

I killed him in that park that day