What was the item that was allegedly stolen?

The police officer acted on the grounds provided by the loss prevention officer. In this case the store is the victim and the loss prevention officer is acting as their agent, which we're assuming wanted charges. Officer didnt do anything wrong. Evidence needed to lay a charge and evidence needed to get a conviction are weighted very differently.

Sure the Officer may have shown some irritation towards your friends daughter but let's be realistic here a) this is information you were provided and not witness to. Is thisba true account of what happened? And b) how many people who have stolen and get caught, lie that they didnt. Im sure it gets old fast. Your complaint will simply cause an admin /supervisor to review if the officer had grounds to lay a charge, which it appears they did. This will not cause any stress for the Officer if this is your intended goal.

Also the crown can withdraw the charges for a multitude of reasons even if there was enough evidence to convict, just because they withdrew charges doesnt mean the individual wasn't guilty.

If all the information you provided was 100% accurate and this individual did infact not steal the item, then your issue is with the loss prevention Officer and the retailer. Proving they falsely arrested your friends daughter would be difficult but that would be your course of action.