The reason why many murders take place inside the home is because they take place behind closed doors without any witnesses, which makes it easy for people to commit murder.
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少し長い文章になってしまいましたが...
"The reason why many murders take place inside the home is"=「家庭内の殺人が多い理由は」
"because they take place behind closed doors,"＝「密室で行われるから」
"which makes it easy for people to commit murder."＝「それは殺人を実行しやすくするから。」
ご参考に。
The reason why there are so many domestic murders is because it is easy to kill behind closed doors without any witnesses.
"家庭内の殺人が多いのは、密室で目撃者もなく殺しやすいから"
- The reason why there are so many domestic murders is because it is easy to kill behind closed doors without any witnesses.
- There are many murders that take place inside a home since its a private area and because there aren’t any witnesses.
Murders within the family are common because they can be committed in a closed room with no witnesses.
「家庭内の殺人が多いのは、密室で目撃者もなく殺しやすいから」は、Murders within the family are common because they can be committed in a closed room with no witnesses. と表現できます。
murders within the family は「家庭内での殺人」を指し、common は「一般的である」「よくある」という意味です。committed は「犯される」というニュアンスです。
closed room は「密室」を意味し、with no witnesses は「目撃者なしで」です。
アメリカ合衆国 
