There are plenty of side quests to do in Watch Dogs. One of the most interesting side missions involves some missing people and a serial killer. There are six of these missions to complete, and they become unlocked after you finish Act I – Backstage Pass or when you find one of the bodies. Completing the series of side quests will get you the bronze trophy or 15 point achievement Darkness Looms. Ready to get started? Here's where you can find all the bodies.
After you unlock the side quest, bodies will appear on your map as a small magnifying glass, but only if you have unlocked the nearby ctOS Tower. There is also a known glitch where the icons will not show up. When looking for the bodies, you don't need to worry about what order you find them in. The audio logs will play in the right order no matter what. After you find all the people and get all the audio logs, complete Hope is a Sad Thing to unlock the last bonus mission and get the trophy.
Go to the northwest section of Pawnee. You need to find a train car along the tracks with the body and audio log inside.
Annie is also found in Pawnee. You can find her on the dirt path between the trailer park and the Crazy Moose Inn. Find the cabin with a mounted moose on it and go inside. Don't forget to grab the audio log.
This one is located in Brandon Docks, on the south side of the bridge. Go towards the water and find an area towards the back, where you can climb up. Climb up and find the audio log and the body.
This body is also at Brandon Docks. Take your boat to the south side and use one of the canals to reach a burned out factory. This is where the body and audio log are located – up on the second floor.
This one is found in The Loop district. Get a boat and go to the small island that is off the east coast. Once there, check the shed for the audio log and body.
Use your fast travel to go to the ctOS tower in the northern area of Parker Square. From here, you'll need to follow the trail to the north to reach a blocked tunnel. Inside is Kate and another audio log.
After you've found all six women and audio logs, and completed Act III, you'll be able to confront the Finger Paint Killer. Go to the trailer park to start the bonus mission. Take out your phone and start tracking either the killer or his victim. Tail them and make sure you have the right guy. Make sure you don't get spotted too early – you need to wait until his profile turns red in order to intervene. Use your tools to profile the killer. Once you can, take him out (watch out for the victim!). When all is said and done, hack the killer's phone to get your rewards. You'll get the trophy/achievement and a sweet new pistol.