When you break the law, your character gets a bounty. Depending on the severity of the crime, guards will either attack you (usually as a response to an assault or murder of an NPC) or arrest you (usually as a result of minor crimes).
To get this easy trophy, go to any city and look for owned containers (crates, bags, barrels) located out in the open (avoid closed places like inns). Some stores at the markets will have weapons or armour exposed on tables. You will recognize the container or item is owned because a "STEAL" text in big red letters will appear next to the item or container. Loot the said item or container, making sure an NPC is around and you're in their line of sight. As soon as you do, you'll get a bounty on yourself. Next, go and look for a guard. They will stop you and give you at least two options: pay your bounty or flee. Choose the latter. The guard (and all guards nearby) will attack you on sight. Now you need to escape the area, preferably even leaving the city. DO NOT ATTACK THE GUARD, as they are basically unbeatable. Just go away. If the guard kills you, they will take the money from your corpse and your bounty will be paid, and you'll have to start over again. The guard will start to root you so you'll have to break free, otherwise you'll be a sitting duck. If your character is low level, chances are you'll run out of stamina, so DO NOT RUN, instead JUST WALK, and keep your stamina for when you have to break free. If there are rivers or lakes or sea, a good trick is to swim, as the guards will be unable to follow you. Also, avoid other guards, as if they see you they'll start to follow you as well.
After you escape the area, the guards will give up and you'll unlock the in-game achievement and the trophy.