You do have to roll your window down for police in Arkansas.
When you get pulled over in Arkansas you must roll your window down for the police, immediately after being pulled over.
The police need you to roll your window down, so they can hear you and interact with you.
If you refuse to roll your window down for police in Arkansas and many other states you can get obstruction charges and escalate the traffic stop and it could result in the police breaking your window and pulling you out of the vehicle and arresting you.
It's simply easier to just comply during the traffic stop and being nice to the police can often get you on your way faster and the officer may not even write you a ticket in some cases and may simply send you on your way with a warning.
When being pulled over, you should pull over as soon as the police light you up and or turn on the siren.
Once pulled over, turn your engine off and roll your window down completely as the officer approaches your vehicle.
Turn on your interior light if stopped at night.
Keep your hands visible and place your hands on the steering wheel.
Don't get out of the vehicle unless the officer asks you to do so.
And don't make any sudden movements.
Police have the right to protect themselves and a closed window can be seen as a safety risk.
Officers are also legally allowed to order you to roll down your window to ensure officer safety and even the Supreme Court has also ruled that this is a minimally invasive request from the officer.
If you ignore the police officer's request to roll your window down or you ignore the polices order to get out of the vehicle or show your drivers license and registration and insurance you can be charged with obstruction and get some serious charges.
Never argue with the police at the traffic stop, simply comply and then take it up in court later.
It's always best that you comply with the officer's orders and then resolve any of the legal questions and issues later in court.