Talk to the Cops / Speak with Barry
Exit your apartment and speak with the cops standing outside a door and offer to help them. After the conversation has come to a close, go over to room 0613 and knock. Unfortunately, he won’t answer the first time around, so move away and skip 3-4 hours of time and try again.
Once he lets you in, sit down on the table and speak with him. If you choose to ignore the optional dialogue options the conversation will come to a close a lot quicker and you’ll just need to fill Petrova and Mendez in to complete the job. However, if you choose to ask all the optional questions an option to find Barry’s Niche and discover more details on Andrews death will appear.
Head over to the marked location on your map and you’ll discover who Andrew really is. Finally, return to Petrova and Mendez and fill them in to finish the job.