So far, the police investigation has drawn a blank.

到目前为止警方的调查毫无结果。

He agreed to cooperate with the police investigation.

他同意配合警方调查。

A police investigation yesterday absolved the police of all blame in the incident.

警方昨天的调查为其开脱了在这件事故中所有的责任。

The police investigation is ongoing.

警方的调查在持续进行中。

A police investigation is underway.

警方正在调查此事。