The man involved in what Baltimore County police were calling a murder and attempted suicide in Catonsville died last week. Sean Vanlandingham, 22, the man who sustained an apparent self-inflicted gunshot wound in the case, died Saturday. Kaylie Logston, 21, was found fatally shot inside a home on Hillside Road on May 14. Detectives said police were notified that Vanlandingham was in a relationship with Logston. No further information was immedi…