(idiom literary) The broad, far-reaching power or influence of the police or legal system. FIG the police, the law.
（习语，文学书面语）警察或法律制度的广泛而深远的权力或影响（法网恢恢）。比喻警察，法律。

例句：

You can’t escape the long arm of the law (= the police will catch you if you have done something illegal). 法网难逃。

There is no escape from the long arm of the law. 法网恢恢，疏而不漏。

He had been living in England under a false name, for several months when the long arm of the law finally caught up with him. 他隐姓埋名在英国住了数月，可最终还是逃不脱法律的制裁。