YOU SAID:

The police plan to investigate this

INTO JAPANESE

警察はこれを調査する計画

BACK INTO ENGLISH

The police plan to investigate this.

INTO JAPANESE

警察はこれを調査する予定です。

BACK INTO ENGLISH

The police are going to investigate this.

INTO JAPANESE

警察はこれを調査するつもりです。

BACK INTO ENGLISH

The police are going to investigate this.