Although he was innocent, the police arrested him. For the police, his existence was not very convenient.
"Although he was innocent, the police arrested him. "=「彼は無実であったが、警察は彼を逮捕した。」
"For the police, his existence was not very convenient."＝「警察にとって、彼の存在はあまり都合のいいものではなかった。」
★"his existence was not very convenient"とはやや遠回しな言い方ですが、警察にとっては邪魔な存在、という意味は伝わるフレーズです。
The police arrested him, even though he was innocent, because his existence was annoying them.
「彼の存在が邪魔だった」＝ "His existence was annoying/inconvenient"
「無実なのに逮捕した」＝"Even though he was innocent, they arrested him"
そして、
「警察は彼の存在が邪魔なので無実なのに逮捕した」＝ "The police arrested him, even though he was innocent, because his existence was annoying them."
ご参考になれば幸いです。
Even though he was innocent, the police arrested him because of what he was doing.
Although he didn't do anything wrong, the police placed him under arrest because he was getting in the way of the police.
ーEven though he was innocent, the police arrested him because of what he was doing.
「彼は無実だったが、彼の行いのために警察に逮捕された。」
ここでは「彼の行い・行動のため」と曖昧に言ってみました。
innocent 「無罪の」
arrest 「逮捕する」
ーAlthough he didn't do anything wrong, the police placed him under arrest because he was getting in their way.
「彼は何も悪いことはしなかったが、彼は警察の邪魔をしたため、逮捕された。」
didn't do anything wrong で「何も悪いことをしなかった」＝「無実」とも言えますね。
place someone under arrest で「逮捕する」とも言えます。
get in one's way で「邪魔をする」
ご参考まで！
アメリカ合衆国 
カナダ 
