Noun
だれか
うちの家族の誰かが、母の死にあの善良な外科医が関与していると訴えたんですか？
Did someone in my family accuse that excellent surgeon of contributing to our mom’s death?
誰 is who, 誰か is like asking "who?" If you don't know who it is, you just know it's someone.
The reading comes from the reading you learned with the kanji.