YOU SAID:
Labs have found rats are slay.
INTO JAPANESE
研究所はネズミが殺されていることを発見しました。
BACK INTO ENGLISH
The laboratory found that the rat had been killed.
INTO JAPANESE
研究所はネズミが殺されたことを発見した。
BACK INTO ENGLISH
The laboratory found that the rat had been killed.
That didn't even make that much sense in English.