I've found the best way to do this is to check out the detached houses around the centre (ish) of the first island.
You'll see people coming and going from the houses, especially at dawn and dusk.
When someone leaves the front or back door, or if someone's heading towards it, clobber them with whatever melee weapon you like to knock them unconscious. Now press
to check their inventory, and they should have a house key on them to the property you're at. Case the joint to make sure nobody else is inside, then press
by any of the doors to get in without triggering the alarm.
You can take as much time as you want to move from room to room, just make sure the amount of goods you steal is valued at a total of $100 or more. Pretty easy in the big houses, as they often have jewellery and silverware to nick.
Once you're sure, leave the house via the most incongruous entrance.
If you do that without getting a wanted star, BOOM! Another easy but fun achievement in American Fugitive.