Watch Dogs

There are 3 stages that must be taken before you get the police on you and a total of 5 wanted levels. For this achievement you'll be utilising the first 2 and making sure the police do not find you. There are also 2 things you'll need for this achievement and that's a decent weapon - highly recommend an assault rifle - and about 3/4 EMP gadgets.

The first part is causing trouble. You'll notice on your wanted level bar that it'll be white and this is where you need to keep it all the way up until the 5th square is highlighted. Use your assault rifle and kill as many civilian NPCs as possible as fast as possible. The longer you take, the harder the next bit below will be. While doing this, you'll notice that some red triangle icons will pop up on your screen and a red bar will be filling up around them. This is a civilian NPC calling the police and you cannot let them do this. If the bar reaches all the way around before you reach the 5th wanted level, the call will go through and the 2nd phase will take place - which you don't want. So when you see one, located the NPC and kill them quick. If you take a long time killing people, these calls will happen more frequently and will be harder to take care of, so the faster you go, the faster the bar will increase meaning you do not have to worry about multiple calls happening all at once.

Once the 5th square of the wanted level has been reached, find a vehicle (a fast one) and wait for one of the civilian NPCs to make a call. Do not kill them and let it go through and the second phase will start. Once the police have been alerted, you wanted level bar will turn to yellow and some yellow circles will pop up on your mini-map. You're now being scanned by the police and they're searching for your location. You'll also notice that next to the wanted level bar, will be a percent meter going up from 0% - 100%. The longer you stay within any one of those circles, the percentage will increase, and as you're at the highest wanted level it'll be faster than if you were on the 1st. The percentage will only stop if you get outside of the circle.

Once the scan starts, just drive trying to dodge the circles that pop up around the maps. If the the percent meter is getting a little too high for your liking, then use one of your EMP gadgets. This will cause a downtime in the scan, meaning you can drive to another location and out of the way of them. Once you've made it a good distance away from the scan and out of their range, they'll stop looking for you and the achievement will unlock. If by chance the meter does reach 100%, then you'll go into full blown wanted mode, the wanted bar will turn red and you'll have to either escape for the 'Free Radical' achievement, or die and start again.