Murderer, Killer
noun
You've hopefully seen 殺人 (murder) from level 13. So, someone who does murder is what? A murderer.
さつじんしゃ
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
この殺人者は、有名なシリアルキラーです。
This murderer is a notorious serial killer.
信じてください。息子は誰かに殺人者に仕立て上げられただけなんです。
Believe me, my son was just framed as a murderer by someone.
あなたは家族が殺人者だった人の苦しみについて、考えたことはありますか?
Have you ever considered the pain of someone whose family member was a murderer?