Why? Lest people mistakenly think that the headline is referring to the organization of all police on the globe ever?
When you see a news article about "Police say [whatever]" it is assumed that a particular organization is saying it. There isn't a global organization of police for it to be confused with.
When you see a news article about "Police say [whatever]" it is assumed that a particular organization is saying it. There isn't a global organization of police for it to be confused with.