The grandparents and father of a 15-month-old girl who in May was mauled by the family's pit bull have been arrested and charged in the deadly dog attack.

Leticia I. Mesa, 52, Arthur "Arturo" Mesa Sr., 57, and Jesus Mesa, 21, all residents of 819 Stone Canyon Drive in Las Cruces, were arrested Monday evening on warrants. Leticia Mesa, the paternal grandmother of Jazilyn Nevaeh Mesa, who died in May following the dog attack, is charged with negligent child abuse resulting in death.

Arthur Mesa and Jesus Mesa, the young girl's grandfather and father, respectively, are charged with one count each of possession of a dangerous dog resulting in death.

The death of Jazilyn Mesa has been under investigation by Las Cruces police detectives and prosecutors from the Third Judicial District Attorney's Office since the attack.

Shortly before 11:30 a.m. Tuesday, May 8, Las Cruces police were called to the Mesas' home by a neighbor who reported hearing Leticia Mesa screaming for help. The neighbor, 69-year-old Barry Snyder, saw that the 2-year-old dog named Tyson was attacking the girl and that Leticia Mesa was trying to cover the child.

Snyder retrieved a .45-caliber handgun from his home, called 911 and went to the aid of the girl and her grandmother. Detectives learned that Snyder entered the backyard and fired the first shot as the pit bull ran at him. The initial shot is believed to have missed the dog and instead struck Leticia Mesa's thigh and foot.

Snyder fired four more rounds at Tyson as the dog ran to a side yard. Snyder followed Tyson and fired two more rounds, which proved to be deadly for the 90-pound pit bull.

Jazilyn Mesa was rushed to Mountain View Regional Medical Center in Las Cruces where she died. Leticia Mesa was transported to University Medical Center of El Paso.

Investigators learned from interviews with several neighbors that the Mesas' pit bull showed signs of aggression toward them or their dogs in the past. One neighbor who had concerns about the pit bull's propensity for violence told detectives that Leticia Mesa revealed that Tyson had previously attacked another dog that also belonged to the Mesas, leaving it with a severe scalp injury.

A veterinarian who over the years cared for several dogs that belonged to the Mesa family told detectives that Tyson showed signs of aggression and had to be muzzled the one time it was treated at the office.

Jazilyn Mesa's mother and maternal grandparents also expressed concern about the pit bull and, prior to the young girl's Jan. 26, 2011, birth, asked the Mesa family to get rid of the dog. When the Mesa family refused to get rid of the dog, Jazilyn's mother demanded that Tyson not be allowed anywhere near her daughter when the young girl visited the Mesas' residence and that the dog be kenneled when Jazilyn was visiting the home.

Detectives learned that Jazilyn's mother -- who did not live at the Mesas' home -- was unaware of the dog's history of violence but was concerned for her daughter's safety because of Tyson's size and because the dog appeared to be rambunctious and untrained.

Investigators interviewed Leticia Mesa at least twice and said her statements regarding the events that led to the deadly attack were inconsistent. Detectives also found inconsistencies in Leticia Mesa's statements on whether she knew that the dog showed signs of aggression prior to the deadly attack.

The New Mexico medical investigator's office ruled that Jazilyn Mesa, who weighed only 23 pounds, received multiple injuries to her head, face, torso, arms and legs. All of the injuries were consistent with those of a dog attack.

Leticia Mesa was booked into the Dona Ana County Detention Center with bail set at $15,000.  Bail for Arturo Mesa Sr. and Jesus Mesa was set at $10,000 each.