Police Have.....vs Police Has [duplicate]

The following dictionary extracts clearly indicate that police is treated as a plural noun.
(The extracts are from the British English entries, but the corresponding American English entries also indicate that the usage is as a plural noun.)

police (Cambridge Dictionary)
noun [ plural ]
Example sentences:
The police are investigating fraud allegations against him.
The police are appealing to the public for any information about the missing girl.
When she was stopped by the police for speeding, she gave them a false name and address.

police (Oxford Dictionaries (ODO))
noun [treated as plural] (usually the police)

(This question is actually just a 'general reference' question which could be answered by looking in a dictionary.)

The closed question Collective noun “police” — singular or plural? addressed the same question and provided a similar answer.

The question Why police used as singular in this link? indicates that both singular & plural usage for police are common in Indian English.

Related (from ELL): “police are” or “police is”

The BBC's web site uses "is" as in the following examples (which I found using this Google search https://www.google.fr/search?q=site:bbc.co.uk+%22police+is%22):

• Metropolitan Police is accused of phone-hacking failures
• Nottinghamshire Police said it would expand its …
• South Yorkshire Police is yet to comment.

All the above are singular.

But the subtitle of the first title above is as follows, using the plural "have" instead of "has",

The Metropolitan Police have been accused of …

So it's presumably, "Devon Police is", and, "The Devon Police are".

The reason, I assume, is that in the second case, "The Devon Police" refers to a collection of several police-persons in Devon, or members of that group; whereas in the first case, it's the name or title of a/the single entity or organization unit which employs them ... similar to, for example, the British Gas web site saying,

British Gas is the largest UK energy and home services company.

... rather than "British Gas are" (because the name refers to or identifies a single company, not to a group of people).

Since you asked about "Devon Police", "is" can be found on the Devon & Cornwall Police web site too:

• Devon & Cornwall Police is a member of the LRF
• Devon and Cornwall Police is hosting a public event
• Devon and Cornwall Police is teaming up with partner agencies
• "Dorset Police and Devon & Cornwall Police is committed to achieving a truly representative workforce"