警犬使用與搜索、臨檢——美國法對我國法制之啟示

Dog Sniffs and the Fourth Amendment to the United States Constitution- Implications to Taiwanese Norms

近年來，國外警方在維安執法實務上，除仰賴新興偵查及鑑識等科技外，常見者亦有依賴警犬執行相關嗅敏反應作為調查毒品等違禁物、偵測炸彈及爆裂物等反恐犯罪之偵查輔助工具。以往對於使用警犬以預防犯罪或偵測犯罪，或許因為執法效率之關係，並未引起法律界的探討，然隨警犬使用之頻繁率應增加，警犬使用之合憲及合法性問題，逐漸浮上檯面，對於此等輔助偵查動物所為之相關行為，是否當然合法及合憲，其行為之本質為何？是否構成侵害人民憲法所保障之權利，而應先取得搜索票，方得由警犬執法，或其本屬於合憲行為，關於上述諸問題，殊值探討之。本文藉由美國聯邦最高法院歷來判決，理出相關脈絡探討警犬使用之本質與搜索及臨檢之法律關係，首先，應先探究其是否侵害憲法保障之公民基本權利，若屬可能，係何種權利遭侵害？是否可以不分情形，一律認定警犬使用必然合於或侵害憲法上所保障之權利。其次，藉由析論行為本質，探究其與搜索及臨檢處於何種關係，是否應依據不同類型，區分「無令狀警犬嗅聞」或「有令狀警犬嗅聞」之情形，以建構類型化的警犬使用，使警犬執法合於憲法規範之誡命，不至於侵害人民基本權利。最後，藉由上述分析，綜整美國法制架構，以之作為建構我國法制之借鏡，最後並區分臨檢及住宅外嗅聞情形下，建構類型化的警犬嗅聞執法。

In recent years, foreign law enforcement practices have relied more heavily on dog-sniffs as a tool to investigate crimes involving terrorism, explosives, and drugs. In the past, owing to the effective enforcement of dog-sniffs, the technique was seldom a problem for legal academia. However, with an increase in the frequency of dog-sniffs as the technique to investigate crimes, their constitutionality and legality have risen to the surface of the legal world and practice. Whether the enforcement of dog-sniffs encroach upon fundamental human rights protected by the Constitution is an issue that has triggered many questions concerning if they constitute a violation of the United States Fourth Amendment rights. Should they be deemed as a search? Does using dog-sniffs require a search warrant? This article analyzes the nature of dog-sniffs, used by law enforcement, through United States Supreme Court precedents, and explores their involvement with fundamental human rights, including the right to privacy and the property right, protected by the Fourth Amendment. Furthermore, it analyzes facts within various types of cases, separating and categorizing the disparate types of facts into either warranted or warrantless exemplifications. Lastly, this article concludes with distinguishing two types of facts, including “stop and frisk” and the area “immediately surrounding and associated with the home” in order to establish proper guidelines for law enforcement practice and court postures in Taiwan.