刑事案件數位證據之跨境調取──美國法之探討與我國法之反思

Law Enforcement Access to Digital Evidence Across Borders in Criminal Proceedings: A Comparative Perspective

網際網路資通訊服務所產生的資料，可能成為刑事審判程序中藉以證明待證事實的數位證據，由於其儲存地不受國界限制，國際上或有透過國際刑事司法互助來取得。近年來數位證據的調取需求快速成長，如何更有效率地調取境外的數位證據已成各國的重要課題。美國制定的雲法案（Clarifying Lawful Overseas Use of Data Act, CLOUD Act）授權聯邦政府與他國政府簽署雙邊協定，令雙方得直接向對方境內的服務提供者調取證據，美國與英國簽署的雙邊協定便是一例。本文在觀察我國跨境調取數位證據的途徑後，發現實務已有相類的取證模式，惟仍應法制化以提升執法的穩定性，爰以美國立法例與美英兩國的雙邊協定為基礎，對我國相關法制提出具體的建議。

Electronic data produced by service of information and communication technology may serve as digital evidence in a criminal trial. Since electronic data is often stored across territorial borders, states have employed mutual legal assistance (MLA) process to collect overseas data. Under increasing pressure from the growing need for timely access to such data, several initiatives seek to respond to the perceived challenge. The CLOUD Act enacted by the United States Congress is one of them, which authorizes the U.S. government to sign bilateral agreements with qualified foreign governments. The agreements provide a direct access mechanism for each party to compel production of data from providers located in the other party. This article explores the approaches adopted by the law enforcement to access data across borders and highlights their limits. This article also offers a way forward by analyzing the U.S.-UK bilateral agreement in a comparative perspective.