It’s legal to wear a badge in New York State but most process servers choose against it. Real law enforcement personnel don’t like to see this as they assume the server is trying to impersonate a cop. In New York, just seeing the badge from a distance would cause most people to assume the police, and it’s never a good idea to give that kind of wrong impression. Philip J is correct: we need to approach process serving situations like salespeople and “appearances count”. In my experience, the best way to elicit useful information from defendants, co-occupants and neighbors is to put them at ease and keep them relaxed. Being straightforward and genuinely polite is more efficient and effective than intimidation.