同意刘冬老师的分析，.caught posing as firefighters and entering properties 是过去分词短语作后置定语，相当于定语从句的省略，即：

caught posing as firefighters and entering properties

=who were caught posing as firefighters and entering properties

另外补充以下类似例句供参考：

1. Athletes caught taking drugs should hang their heads in shame.

=Athletes who are caught taking drugs should hang their heads in shame.

被査出服用违禁药品的运动员应该感到羞愧。

2. The public rarely feels sympathy towards politicians caught behaving badly.

=The public rarely feels sympathy towards politicians who are caught behaving badly.

公众很少对行为不端的政客表示同情。

3. The university publicly censured the students caught cheating in the exam.

=The university publicly censured the students who were caught cheating in the exam.

这所大学公开谴责考试作弊的学生。

4. The National Basketball Association announced a lifetime ban on players caught dealing in narcotics.

= The National Basketball Association announced a lifetime ban on players who were caught dealing in narcotics.

美国国家篮球协会宣布，被发现从事毒品交易的球员将被终身禁赛。

1.caught posing as firefighters and entering properties作何成分？（这是过去分词词组/短语作后置修饰语/定语）

2.posing… … properties 又作什么成分？（是这个名词词组two individualsThey included two individuals caught posing as firefighters and entering properties.

句子摘自《 caught posing as firefighters and entering properties中two individuals的补足语）。

3.全句意思:他们中包括两名冒充。。。