The police have detected the trace of the murderer after several days of investigation.

警察经过几天的调查，发现了凶手的踪迹。

youdao

The primarily academic purpose of the trace investigation of Yixu is to analyze objectively the vicissitude and reality of Yixu village by applying both the diachronic and synchronic approaches.

将共时性的剖析和历时性的考察相结合，力求客观地描述和分析义序乡村的现实图景和真实变迁，是作者义序追踪研究的真正学术目的。

youdao

Methods Visualization, investigation of mouse trace, using powder, Numbers of digged holes, saturated bait consuming.

方法目测法、鼠迹调查法、粉片法、掘开洞数法、饱和食饵消耗法。

youdao

The Maritime and Coastguard Agency launched an investigation into the first spill, but has since said it had been unable to trace the source of the pollution and confirmed it had closed the investigation.

BBC: 'Sticky substance' birds rescued in Devon and Cornwall

Police are also keen to trace a mountain bike in connection with the investigation.

BBC: Nellie Geraghty: Man charged with manslaughter

After the first incident, the MCA launched an investigation into the spill, but has since said it had been unable to trace the source of the pollution.

BBC: More 'sticky substance' birds found in Devon and Cornwall