The Dallas County Medical Examiner's Office has ruled the cause of deaths of four people found inside a Mesquite home as a murder-suicide.
The Dallas County medical examiner said the deaths of 44-year-old Marcelo Vazquez, 18-year-old Alejandro Roman Vazquez and 21-year-old Paulina Belen Vazquez have been ruled as homicides.
The death of Angelica Vazquez, 43, wife and mother, has been ruled as a suicide. A handgun was located on the floor in the master bedroom near her body, according to Mesquite police.
Detectives are still investigating a motive.
Mesquite police say the four bodies were found inside the home in the1400 block of Paintbrush Street four days after receiving a 911 call reporting gunfire.
Police officials told NBC 5 that officers were called to the home at about 6:30 a.m. Saturday after someone reported hearing gunfire.
The responding officers said they did not see anything unusual and did not see signs of forced entry. They said they were unable to reach the residents.
The officers left after talking with a neighbor who reported hearing and seeing nothing out of the ordinary. Officers returned to the house two more times Saturday morning but were still unable to reach anyone who lived at the home.
Police said the same officer who initially responded to the call returned to the home Wednesday morning and noticed mail in the mailbox and newspapers in the yard. Officials then made the decision to enter the home. Once inside, police discovered the four bodies.
The bodies of two men and two women were found in four separate rooms of the house. Each victim had been shot, Lt. Bill Hedgpeth said.
Police identified the victims on Thursday.
"We process every death scene the same way," he said. "We look for any type of forensic evidence and any type of evidence at all that would lead us in a particular direction. We keep an open mind about it, because we want to see where that evidence will take us."
Police have released few details about the case.
A family friend told NBC 5 that Paulina attended the University of North Texas and that her brother Alejandro graduated from Mesquite High School last year.
"It was just what I thought was just a happy family," said Gustavo Herrera, who told reporters he went to his senior prom with the 21-year-old victim.
Herrera and other friends were gathered outside of the victims' home until well past dark Wednesday night.
"There wasn't anything bad going on with the family," said neighbor Alex Turrubiartes, who graduated high school with the 18-year-old. "There was nothing -- no trouble, nothing; normal."
The investigation into the deaths is ongoing.