Authorities in Texas have arrested three suspects accused of abusing a special needs teen for months, ending in her death just over a year ago.

According to KHOU, the 14-year-old victim’s October 2016 death was ruled a homicide caused by ingesting an unprescribed blood pressure medication.

Police responded to the teen’s Spring home after receiving a report of an unresponsive person. She was pronounced dead upon arriving at an area hospital.

Anthony Jackson, Tommieretta Gunner and Marreissa Jones were arrested last week on suspicion of injury to a child after investigators found a pattern of abuse dating back months prior to her death.

Reports indicate Jackson is the victim’s father and Jones was a health care provider working with the disabled girl. Gunner was one of her caretakers, according to the Houston Chronicle.

The abusive acts allegedly inflicted on her by the trio of suspects included shocking her with a stun gun on multiple occasions. Investigators say Jones threatened the teen’s life at least 15 times in the three months preceding her death.

Surveillance footage recorded within the home revealed use of the stun gun, police say. The video also reportedly captured someone giving the victim the medicine officials say killed her.

In the footage, the girl could reportedly be seen acting lethargic and incapacitated multiple times — allegedly after taking the blood pressure pills — in the months before she died.

The investigation remains open, according to police. Anyone with information about the suspects or the allegations against them is encouraged to call 936-760-5800 and reference case 16A190412.

[Featured image: Anthony Jackson, Tommieretta Gunner and Marreissa Jones/Montgomery County Sheriff’s Office]