And so, so many questions.
That's what Chicago authorities, not to mention friends and relatives of the victims, have said nearly a week after police found all six bodies inside a brick bungalow in the Illinois city.
"We are not ruling anything out or anything in at this point," Chief of Detectives Gene Roy said.
Detectives on Wednesday went in and out of the Gage Park home, where a police car was parked outside. Up until now, authorities have said the grisly deaths could be the product of anything from domestic violence, to a robbery to something else entirely.
However, they were not random, with Roy saying authorities assume "the family was targeted."
Why, no one is saying.
Monica Arias told CNN affiliate WLS
she never heard any signs of trouble coming from the single-family home: "No screaming, no fighting, we heard nothing." Fellow neighbors described victims as family oriented, with Fani Maldonado calling one of them her "best co-worker" washing windows at O'Hare airport.
"It was just really a shock," 24-year-old Adilene Magana, who lives across the street, told CNN on Wednesday. "It's just so horrible they would kill children."
Magana had no suspicions of anything awry.
"We could see people come out of the home and go to their cars and always mind their own business," she said.
1 shot, rest killed by 'blunt' or 'sharp force injuries'
Markita Williams knocked on the family's front door last Wednesday after noticing a van outside, one she worried might belong to someone inside and be towed.
No one answered.
"Everything was closed up tight," said Williams, who has lived directly next door for three years. "They always had their curtains open -- you could see directly into the house from the front and on the side."
Police showed up the next day after someone called 911 worried that his or her co-worker, who lived there, hadn't shown up for work two days in a row, interim police Superintendent John Escalante said.
They arrived to find six people, all of whom were killed in what the Cook County Medical Examiner's Office ruled were homicides. But not all the same way.
Maria Herminia Martinez, 32, died of multiple gunshot wounds. The cause of death for two others, 58-year-old Rosura Martinez and 38-year-old Noe Martinez Jr., was listed as "multiple blunt and sharp force injuries due to (an) assault." And the remaining three victims -- Alexis Cruz, 10; Leonardo Cruz, 13; and Noe Martinez Sr., 62 -- all died from "multiple sharp force injuries," according to the medical examiner's office. In a police dispatch call, an officer indicated at least one of the victims had been stabbed.
Authorities haven't identified any suspects yet, saying only they don't think there's a threat to the surrounding area. Chicago police spokesman Anthony Guglielmi told CNN on Saturday that investigators "are reviewing the autopsy reports and moving from evidence recovery to a comprehensive criminal investigation."
And they're not the only ones trying to make sense of this travesty.
"It's just one of those things I can't explain. Good family, good kids," Williams said of her late neighbors. "I just don't know."
Forensic evidence prioritized
On Tuesday, Chicago police met with the Illinois State crime lab and asked them to prioritize some of the forensic evidence collected from the scene.
"There was a lot of physical and biological evidence," Guglielmi said.
"Detectives triaged what was most important to the investigation and the state will help prioritize it. We're now eagerly awaiting the results that may determine how many people may have been involved."
He says police have also recovered a large amount of video from various sources including CTA buses that traveled up and down California Avenue, from pod cameras in the neighborhood and also some private video.
"There is literally days of footage that detectives are now sifting through that makes us quite optimistic."
'A complex investigation'
The deaths echoed far and wide, with the Mexican consulate in Chicago cooperating with authorities there and working with surviving relatives to fly all six bodies back to Mexico.
Marcelino Miranda, the consulate's legal counsel, told CNN that the slain children's father is arriving Thursday in Chicago after obtaining a special immigration permit. Those two bodies and that of their mother will go to Morelos state, while the three others will be flown to Guanajuato state -- all likely in the next two weeks, Miranda said.
In the meantime, those in Illinois will get a chance to say their own goodbyes during the Sunday night funeral for all six victims at Chicago's St. Gall Catholic Church.
In the working class southwest Chicago neighborhood they once called home, a steady stream of people offered flowers and prayers at a makeshift memorial outside the residence. Dozens wiped away tears during an emotional vigil Sunday at the same spot
, where six white crosses stood tall in memory of the victims.
In addition to sadness, there was also regret.
"Being so close, we feel like maybe we could have, I don't know, noticed something," neighbor Mayra Diego said.
Roy, the Chicago police detectives chief, has said there were no signs of forced entry into the home -- suggesting someone let the killer or killers in, rather than them forcing their way. The house wasn't ransacked. And the victims were not tied up.
If any one of those facts were different -- if the house was turned upside down suggesting theft was the motive, or if everyone was lined up and killed execution-style -- it might make things clearer.
Guglielmi says police are a little closer to some theories as to what happened inside the house, but police are not yet ready to discuss them.
Instead, as Roy pointed out, "This is a complex investigation."