The Sheriff's Office said the girl later succumbed to her injuries.
The dog owner, Erick Lopez, was taken into custody on Saturday, Jan. 7, The Advocate reports. He was booked into the East Baton Rouge jail on a charge of negligent homicide but was later released on Jan. 9, records show.
According to the Advocate, the girl was later identified as Woodlawn Elementary first-grader Sadie Davila.
Upon further investigation, authorities learned that the girl was playing outside at a relative's home when Lopez's dog, a pit bull terrier, allegedly attacked her. A family member tried to defend the girl by hitting the dog with a cane, The Advocate reports.
The girl reportedly suffered "numerous dog bites to her face and substantial damage to her skull."
The Sheriff's Office said the dog was taken into custody by Animal Control. According to The Advocate, the dog was found with blood around his face and mouth, and there was a "substantial" amount of blood on the yard where the girl had been playing before the alleged attack.
Authorities reportedly concluded that Lopez had "failed to confine or restrain his dog, which unlawfully entered a neighboring property and attacked a 7-year-old female victim, causing her death."
East Baton Rouge Sheriff Sid Gautreaux said in a statement, "This is an awful, heart-breaking tragedy. My heart goes out to this family, and they will remain in my prayers."