3. It argues that since prosecutors do not consume a company's products as part of their investigations, they could be influenced only by the halo effect.

断句：It argues that since prosecutors do not consume a company's products as part of their investigations,// they could be influenced only by the halo effect.

顺译：它认为由于检察官并不购买一些公司的产品作为它们调查的一部分，它们可能会影响 只被“光环效应”。

解析：that since…引导的是宾语从句，顺译即可，that无意义不翻译。

调整：研究(它)认为，由于检察官并不购买那些作为其调查部分的公司产品，因此他们只能受到“光环效应”的影响。