The Harvester

SM10: The Harvester is a side mission in Deus Ex: Mankind Divided. It is available for Adam Jensen to complete during his second visit to Prague. Completing this mission unlocks "The Harvester" achievement/trophy. You must finish this mission successfully (no arrests) to do SM11: The Last Harvest during your third Prague visit.

Walkthrough
When you get back to Prague after Golem City, make your way back to Adam Jensen’s apartment complex, Zelen Apartments. Down an alley next to Svobody Beer you’ll see police tape marking off the alley, but you can enter to find a few police and a neighbor, Daria Myska, standing near the corpse of an augmented journalist, Angela Gunn.

You can talk to either Dective Karl Montag or Daria to start the mission. Daria will say she’s scared and doesn’t want to come forth about if she saw anything and asks you to help out because Adam is augmented like the victim. If you accept, go over and talk to Montag, who’s being leaned on from higher ups to arrest the dead woman’s husband, Johnny Gunn, simply because he’s augmented. Montag will give you the chance to figure out the real culprit, if any, before the husband is arrested.

There are 7 clues in the alley to help your investigation: Adam can also talk to one of the onlookers, Scandalmonger, who’ll suggest another suspect, Radko Perry, a politician, because Angela was about to expose him. If you go back and talk to Daria, she’ll give you a little bit more information, but can only confirm it was a male attacker.
 * Bruises on Angela Gunn’s neck
 * Marks on her arm
 * A needle in her right shoulder
 * An augment smashed into the wall (the blood splatter near the body)
 * An EMP fragment between Daria and the floor grill
 * An ID card near Daria
 * Broken glasses near the trash bags and ID card

Once all clues are collected, talk to Montag again and click through options until you can ask about the MO (modus operandi) and mention some of the items you found, particularly the marks on her body and the needle. This will remind him of a past case and suggests that Adam read the file on it back at the police station. You can also ask about suspects and mention Perry, who the detective doubts but says you can check him out if you want to make sure.

If you want to get the full completionist, make your way over to Perry’s HQ near the pawn shop. You can talk to him, but he won’t reveal his alibi. Get into his basement and use the messenger on his computer. Someone named Ivanka will be on and talk about negotiating. Do question, bluff, then either option to get the alibi. You can also get the blackmail photo out of the safe if you want, but it’s not needed unless you want to have a little chat with Perry about his secret.

Now make your way to northern Prague and the police station. The case file is in the basement lockers in the back. It’ll mention a victim of a possible copycat of a dead killer named Marek Svobotka, aka “The Harvester”. It also notes that certain habits that only a select few knew about from the dead killer's cases were also evident in the newer killings.

Now head out to Johnny Gunn’s apartment. You can talk to him but he reveals he has no alibi as he stayed in his apartment alone all night. If you have the CASIE aug, ask about Belltower then, when the options pop up, select “sympathize” then select “alloy hands” which reveals that he couldn’t have been the killer as the killer left a partial fingerprint behind. If you don’t have the CASIE aug or just want to skip the chat, go to his bed and you’ll see a file up against the cabinet which reveals that his alloy hands have no fingerprints.

Head back to Montag to complete the mission. Choose to exonerate both of them (should be available with your evidence) and select either option after that. Adam will tell Montag all the evidence proves the two suspects, Johnny and Perry, couldn’t have done it. This will finish the mission successfully so you can start SM11: The Last Harvest during the third visit.