Finally the Supreme court stated:

　　The information given to narcotic agent Marsh by "special employee" Hereford may have been hearsay to Marsh, but coming from one employed for that purpose and whose information had always been found accurate and reliable, it is clear that Marsh would have been derelict in his duties had he not pursued it. And when, in pursuing that information, he saw a man, having the exact physical attributes and wearing the precise clothing and carrying the tan zipper bag that Hereford had described, alight from one of the very trains from the very place stated by Hereford and start to walk at a "fast" pace toward the station exit, Marsh had personally verified every facet of the information given him by Hereford except whether petitioner had accomplished his mission and had the three ounces of heroin on his person or in his bag. And surely, with every other bit of Hereford''''s information being thus personally verified, Marsh had "reasonable grounds" to believe that the remaining unverified bit of Hereford''''s information -- that Draper would have the heroin with him -- was likewise true.

　　最高法院最后陈述道：

　　由“特别雇员”赫尔夫德提供给禁毒特工马什的信息属于间接听闻信息来自于负责专门调查目的线人而且内容一直准确可靠。如果马什特工不追踪这条信息无疑将会是一种失职。在追踪这条情况时特工确实看见了生理特征、衣着、随身携带物品、以及行动样态符合线人描述的对象，而且其所乘坐的交通工具的班次特征，出现在特定场所的时间地点也和预先得到的信息相吻合；也就是说，特工人员在追踪这条情报时确实本人验证了信息描述的方方面面，唯一未能验证的是嫌疑对象的行动使命目的以及是否随身携带了三盎司海洛因。由于特工已经亲身验证了其他的信息，马什特工已经获得了“合理的依据”相信线人情报中剩下的未能得到证实的部分很可能也是真实的，因此有合理可能相信嫌疑人确实也携带了毒品。

　　In dealing with probable cause, as the very name implies, we deal with probabilities. These are not technical; they are the factual and practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act. Probable cause exists where the facts and circumstances within their [the arresting officers''''] knowledge and of which they had reasonably trustworthy information [are] sufficient in themselves to warrant a man of reasonable caution in the belief that an offense has been or is being committed.