Translation:The police are here!
Chinese often doesn't differentiate between singular and plural nouns, nor does it have articles to modify nouns, so this sentence could mean either "A police officer is here," "The police officer is here," or "The police are here," but the last sentence is most likely when the number of police is unknown. Also, "到了” can be translated as "have arrived" or "has arrived."
Yep. :) Although some news articles in the US and UK have fallen foul of this rule. https://www.google.co.uk/amp/s/blog.oxforddictionaries.com/amp/2011/09/05/agreement-over-collective-nouns/