Decatur police are investigating the city’s second murder in less than a week. According to reports, 23 year old Robert Wesley Johnson was shot in the head in his home on South Sycamore Street and his body was found by his roommate. Macon County Coroner Michael Day said the autopsy will be conducted today in Springfield. An inquest is also pending. Police collected evidence from the scene yesterday afternoon and interviewed neighbors. Just seven days ago, another man, Vinson Banks, was shot on West Cushing Street after an altercation.