I generally agree with the stance that undercover cops should be allowed to lie, since failing to do so would defeat the purpose of being undercover. However, an officer actively arresting someone using their authority as a police officer should be required to be as truthful as possible with the person detained.
I’ll stop saying “defund the police” when “protect and serve” is actually what they do.
https://www.cdc.gov/me-cfs/index.html