Both are correct, like England has lost to Germany in a game of soccer, England have lost to Germany is correct as well depending on the context. Context (1) An uncountable noun as a national team. context(2) Collective noun as players of the team. The British team are changing in the locker room. The police is here ( As a law enforcement agency, even if ' represented ' by a single agent, representative ( person) ). The police are here ( The police personnel in a response team, even if it's ' represented ' by a single member of the team ). A very useful link deliberating on the cultural nuances and biases taking preference in usages. https://english.stackexchange.com/questions/482549/team-is-or-team-are/482567

Hello Rook! The word "police" is automatically the plural form so if you were to use it in singular form you would have to say "policeman" or "policewoman" or "police officer", as you said.

"The police ARE here" is the correct one. You can say "The police officer IS here".