He gave a detailed explanation about the plan.

The prosecutor thoroughly investigated the evidence.

He found evidence to prove his innocence.

We started an investigation into the incident.

The police are investigating the incident.

He submitted personal evidence to support his claim.

The police collected physical evidence from the crime scene.

Whether his new recipe is really delicious or not, the proof of the pudding is in the eating.

We conducted a questionnaire survey for the development of new products.

We need to conduct a factual investigation on this issue.