Business INsider reports 25 year old Fitness YouTuber Erich Stelzer died in police custody in Cohasset, Massachusetts, on Thursday. Police said they responded to a disturbance call and found Stelzer stabbing 24-year-old Maegan Tapley, whom he reportedly had met on Tinder. Police used a stun gun on Stelzer multiple times when trying to control him . Tapley is expected to make a full recovery, and an investigation into Stelzer's death is ongoing, according to authorities.