Chicago police said they believe six family members found dead in their southwest side home were killed in a "targeted incident," though they're still trying to determine a possible motive.
It's possible someone in the family "was involved in something that could have targeted them," or that the killings occurred during a robbery or a domestic incident, police spokesman Anthony Guglielmi said late Friday.
Police found the six people -- two children, two women and two men -- dead on Thursday after one of the men's co-workers called the emergency dispatcher to report he hadn't shown up to work for two days.
Authorities initially said it was possible one person killed the other five before taking his or her own life. But the Cook County Medical Examiner's Office on Friday ruled their deaths homicides, saying five were stabbed to death and the sixth died of multiple gunshot wounds.
Police have added extra patrols as a precaution, though Guglielmi on Friday repeated earlier police statements that they don't believe the general public is in danger. There was no forced entry into the home and the house wasn't ransacked.
"This appears certainly centred and targeted on that family, and what we're trying to do is figure out why," he said.
Officers are exploring the backgrounds of the six victims, including talking to other family members and friends, Guglielmi said.
Authorities haven't released the identities of the victims, though the medical examiner's office described them as a middle-aged man and woman, an older man and woman, and two boys.
They said the middle-aged woman was shot to death, while the older woman and a middle-aged man suffered blunt trauma in addition to stab wounds.
The boys were 10 and 12.
A relative said six people lived in the home -- a couple, their son, their daughter and the daughter's two children.
"They were a normal family. Everything was fine," the relative, Noemi Martinez, 29, said from Dallas during a phone interview in Spanish. She said her husband was a nephew and cousin of the home's residents.
Martinez said the father worked at a factory in Chicago and the mother was a housewife. They were originally from the Mexican state of Guanajuato and had lived in Chicago for about a decade, Martinez said.
"Right now, we just want to know who did this. They didn't deserve this. We don't understand what happened," she said.
Associated Press writer Ivan Moreno in Springfield, Illinois, contributed to this report.
