Reported Speech using "have" and "had"

Question

Direct Speech

Police said "We have arrested the terrorist"

Indirect Speech/Reported Speech.

a) Police said they have arrested the terrorist

b) Police said they had arrested the terrorist

In indirect/Reported speech we use the past tense. This is to describe an incident that happened in the past. But I read some news where the reporter has used have arrested instead of had arrested.

Please help me to understand when to use sentence a) and b) in reported speech? According to me sentence b) is incorrect.

Answer 1

Police said they have arrested the terrorist.

According to grammar, ther's no need to bachshift the verb in reported speech if what a person said is still true or relevant. For example, if the terrorist has just been arested and is still in custody, not released, you don't need to backshift have.

However, to do so is optional: you can use have or had.