UPDATE 3/14: The Dallas County Medical Examiner ruled Thursday that 43-year-old wife and mother Angelica Vazquez shot and killed her husband and their two children before taking her own life in their Mesquite home.
The bodies were found Wednesday.
Three of the four victims were identified Thursday morning as Marcelo Vazquez, 44, and his children, Paulina Vazquez, 21, and Alejandro Vazquez, 18. Each death was classified as a homicide.
Angelica Vazquez, 43, the mother of Alejandro and Paulina and wife to Marcelo, was identified in the afternoon and killed herself, the medical examiner said.
A handgun was found on the floor near her body, said Bill Hedgpeth, spokesman for Mesquite PD. Investigators are still without a motive in the crime.
Below is our original report from Wednesday:
MESQUITE — Four adults found dead inside a home in the 1400 block of Paintbrush Street Wednesday morning may have been there since Saturday, Mesquite Police Department spokesman Bill Hedgpeth said.
Late Wednesday, investigators said they needed more time before releasing the names of the two young adults and two mature adults.
Neighbors and friends confirmed to News 8 that the dead are a family of four.
Close friends said a male Eastfield College student who recently graduated from Mesquite High School and his sister, a 21-year-old University of North Texas student, are among the fatalities.
The friend said their parents were also dead; he was said to be a big rig trucker and she worked at a school.
An acquaintance said the mother had recently completed chemotherapy in a battle against cancer.
"I'm just shaking... I can't even express it right now," said Gustavo Herrera, a family friend.
"I don't even know how it happened. It doesn't make sense, really," said another friend, Jasmin Lechuga.
Officers were initially called to the address at 6:30 a.m. Saturday after witnesses said they heard gunshots.
"They checked the residence on the outside. There was no sign of forced entry and everything appeared to be okay," Lt. Hedgpeth said.
Hedgpeth said an officer spoke with a neighbor who did not report hearing or seeing anything out of the ordinary.
Officers left, but returned twice that day to try and get someone to open the door. Both attempts were unsuccessful.
On Wednesday morning at 7:30 a.m, Hedgpeth said one of the same officers returned to the home and observed an important clue.
"They noticed mail in the mailbox that was uncollected and newspapers in the front yard," the police spokesman said. "The decision was made to force entry into the locked home, at which point the officers discovered the bodies."
The bodies of two men and two women were found in separate rooms. A handgun was recovered inside the residence "near one of the deceased," but police were hesitant to discuss details in the case, Hedgpeth said, citing the ongoing investigation.
"At this point, the circumstances surrounding the deaths are undetermined," a police statement said.
The Dallas County Medical Examiner was at the scene.