Caddo Sheriff`s Detectives arrested a Vivian woman for shooting and killing her boyfriend Tuesday night. 78-year-old Margaret L. Fitzgerald was arrested for 2nd degree murder. She is currently receiving treatment at LSU Health Sciences Center in Shreveport. Upon her release, she will be booked into the Caddo Correctional Center on the homicide charge. Detectives say it appears that Fitzgerald shot 53-year-old Roger Guin once and then turned the gun on herself, shooting herself once in the arm and chest. Afterward, she went to a neighbor`s house for help. Fitzgerald was initially taken to North Caddo Medical Center in Vivian, but was later transferred to LSUHC. Guin died at the scene. The shooting occured at Guin`s residence in the 10000 block of Main Street in Rodessa. Detectives say Fitzgerald has provided little information, but it does not appear there was a struggle between the two. A visitor to the house earlier in the evening said the couple had not been arguing. The investigation continues.