On May 4, 1932, a woman named Minnie Jansson became concerned for the wellbeing of her friend, Lilly Lindestrom when she hadn’t seen or heard from her for three days, despite many attempts to reach her. When police arrived at Lilly’s apartment, what they discovered would haunt the Atlas neighborhood for years to come.

Sources:  

• Unsolved Mysteries: The Vampire Killing of Lilly Lindeström | by Michael East | True Crime Detective
• 10 Disturbing Facts Of The Atlas Vampire - Listverse
• The Strange Unsolved Mystery Of The Atlas Vampire (grunge.com)