You said "He should evangelize enthusiatically while off duty and out of uniform."
In the book of Mark chapter 16 verse 15 Jesus is quoted:
"Go into all the world and preach the gospel to every creature."
He doesn't say except when in uniform. He doesn't say except when armed. He doesn't say exept when it offends Druids or Muslims, or ACLU lawyers.
So you'll not be upset should you or your family be pulled over for some violation, whether real or imagined, and a gun-toting officer of the state encourages you to attend his mosque, and suggests that it would be a good idea for you to accept his invitation to the "Religion of Peace" because "the great prophet Mohammed" tells him in the Qu'ran that he must spread the word of Allah, as he casually mentions that he knows your address now?
Yes, he should "Go into all the world and preach the gospel to every creature." per Jesus' instruction in Mark chapter 16 verse 15.
He should also follow Jesus' instruction in Matthew 26:52 "Then saith Jesus to him, Return thy sword to its place; for all who take the sword shall perish by the sword."
It doesn't really matter what it says in the bible in regards to when christians should spread the word.
The problem here is that this officer seems to have used his official position as a way to spread his religious views.
As a taxpayer, I am not interested in public officials using their tax-payer supported positions to spread a certain religious or political agenda.