(CBS) RICE, Texas - A 33-year-old Texas mother shot and killed her husband and her three sons -- ages 4, 8, and 10 -- before killing herself, reports CBS DFW.
"The preliminary autopsies have revealed all three children along with Israel Alvarez died of homicidal violence by gunshot wounds. Guadalupe Ronquillo-Ovalle died of a self-inflicted gunshot wound," according to a statement released by the Navarro County Sheriff's Department.
Investigators say the shootings happened sometime late Thursday or early Friday
They say Ronquillo-Ovalle, 33, did not leave behind a note and there is no clear motive for the shootings at this time. Police say a .22 caliber semi-automatic rifle was used in the incident.
"Certainly we believe it is going to be difficult to find a motive in this case. We're going to be conducting interviews with neighbors, friends of the victims to try to determine if there is any motive that we can uncover in this case," said Sheriff Elmer Tanner, who said deputies will continue to investigate the case as a murder-suicide.
The children did not attend school on Friday -- and a family member found the bodies inside the family's home Sunday evening, after several unsuccessful attempts to get in touch with them, reports CBS DFW.
Sheriff Tanner said each of the victims had a gunshot wound to the upper torso and Ronquillo-Ovalle had a single gun shot wound to the head. Authorities do not believe that there is a suspect is on the loose, or that the community is in any danger. The investigation has been confined to inside the home, according to the station.
Authorities have not released where the bodies were located inside the home, although Tanner said there was no indication that anyone was trying to escape at the time of the shootings.
Two weeks ago, the husband of Ronquillo-Ovalle, 33-year-old Israel Alvarez, was arrested on an assault charge. He reportedly spent two days in jail and was ordered to pay a fine. Investigators say his wife, Ronquillo-Ovalle, claimed he pushed her.
"We cannot determine much from that incident, other than that was an isolated incident involving family violence," said Tanner about Alavarez's recent arrest. "We can only assume that there were problems in the household that led to that case of family violence, and there may have been other incidents that were taking place."
Tanner has called the incident "traumatic" and said in his 25 years in law enforcement he cannot recall an incident in which a mother shot and killed her own children.