まと しぼ
matō shiboru

Godan Verb (ru)
Expression

1. to narrow in (on); to home in; to focus; to target

上手 じょうず弁護 べんご はひとつの かぎとなる証拠 しょうこ まと しぼる。
jōzuna bengoshiwa hitotsuno kagito naru shōkoni matō shiboru.
A good lawyer will always zero in on a key piece of evidence.