日前，广州市公安局加强警力，严厉打击街角抢劫、殴斗等犯罪行为。2006年下半年，五百名特警将上路巡逻，除便衣巡逻之外，在路面上也投入公开巡逻的警力。

请看《中国日报》相关报道：More than 500 special armed police will patrol the streets of Guangzhou in the second half of the year in an attempt to tackle the problem of street crime in the southern metropolis.

The special police force, working with plainclothes police, will mainly patrol commercial streets, railway stations, scenic spots, shopping centres and other busy areas with high crime rates.

想必您已看出，“特警”和“便衣”相应的英文表达分别是“special armed police”和“plainclothes police”。这里提醒大家，写plainclothes时千万要记得在单词末尾加“es”，plainclothes police是集合名词，如果要表达“一名便衣”则应用“a plainclothes policeman”来形容，如：

That plainclothes policeman detained the drugpusher.（那名便衣把毒贩给拘留了。） http://www.51education.net

另外，“便衣”也可说成plainclothesman。