Here are details of an interesting judgement from New Mexico on the issue of probable cause in relation to a drugs warrant. There are a couple of learning points here for all detectives.
Informant Case Law - New York - Probable Cause
Informant Case Law Boston - Protecting the identity of a confidential informant
We are always studying recent court judgements with regard to protecting the identity of an informant. Here is the ruling from Massachusetts where the court ruled to protect the identity of an informant.
Officers managing informants need to read this type of judgement in order to protect informants properly.