The big question that always comes to everyone’s mind after a horrific crime like the mass shooting at Marjory Stoneman Douglas High School is: could this have been prevented?

As we are learning today, that answer is rarely as clear-cut as we would like it to be.

Profiles of the alleged gunman, who was just charged today, note that he was adopted at birth with his biological brother, but that his father died years ago of a heart attack, and his mother just recently passed away. We do not actually have any medical records to support any mental illness as of yet, only anecdotal evidence that his behavior may have escalated after her death.

We don't know that Cruz was mentally ill. He acted "weird," he was "depressed" after the death of his mother. Under those criteria, we're all mentally ill.

— Justin Miller (@justinjm1) February 15, 2018

We know that he was expelled from school, and there were warning flags in his relationships with his peers.

The 19-year-old man, who was described as “weird” and a “loner,” was expelled from the same school he allegedly opened fire on Wednesday. The Sun-Sentinel reported Cruz was expelled for “disciplinary problems.”

“I think everyone had in their minds if anybody was going to do it, it was going to be him,” said Victoria Olvera, a 17-year-old junior at the school.

Olvera said Cruz was expelled last school year because he got into a fight with his ex-girlfriend’s new boyfriend. She said he had been abusive to his girlfriend.

Emily Sucher, a junior at the high school, said she remembered Cruz as “an off kid” who “would smile weirdly, make weird comments.”

Another student, Trevor Hart, said Cruz “seemed like he really didn’t like school.” He also said the teen, who was enrolled in the Army ROTC at the school, had “a bunch of weapons” and often spoke about killing small animals.

Joshua Charo, 16, told The Washington Post that Cruz spoke about “guns, knives and hunting” often and “was into some weird stuff, such as shooting rats with a BB gun.”

Charo said Cruz was suspended from the school for fighting and having bullets discovered in his backpack.

Drew Fairchild, another classmate, called Cruz “a troubled kid” who cursed at teachers often.

As Victory Girl Toni pointed out, there were many cracks that the gunman fell through, and the largest one may have been the YouTube comment that he left on a video posted by Ben Bennight, aka “BentheBondsman.”

So why didn’t the FBI find the gunman at that time?

FBI Special Agent in Charge, Robert Lasky, addresses @bri_sacks scoop about the FBI being warned about a comment about school violence from the shooter’s name in September.

He said the agency couldn’t ID the person.https://t.co/wyzk1ljHrI pic.twitter.com/BB9hgHccha

— Tom Namako (@TomNamako) February 15, 2018

FBI Special Agent Robert Lasky confirms that agency received a tip this year about YouTube user Nikolas Cruz commenting that he wanted to be a professional school shooter, but agents could not verify "time, location, or identity." Still no response from YouTube

— Brianna Sacks (@bri_sacks) February 15, 2018

In a follow up statement, the FBI said it "cannot confirm any further details" when asked what methods the agency used to try and verify the YouTuber Nikolas Cruz's ID back in September

— Brianna Sacks (@bri_sacks) February 15, 2018

People are correctly pointing out that the gunman used his own name on YouTube, and that should have been enough. I decided to run a little experiment of my own. I entered in the name “Nick Cruz” into Facebook’s search. I counted over 70 names and derivations of that name (Nicholas, Nik, Nikolas, Niklaus, etc.) before I thought the point had been proven. Was the FBI supposed to go hunt down all the “Sarah Connor” listings in the phone book? If they did not have at least a location, then the search is a literal needle-in-a-haystack without the assistance of YouTube itself. Now, did the FBI ask YouTube for help? Did YouTube offer any account information, or did they tell the FBI to get a warrant first? We just don’t know – and YouTube has not commented yet.

So that’s where we are. We have students who were concerned, and they said something. We have a school district who knew he was troubled, and they removed him from the school. We have law enforcement who received a tip that might not have been enough to act upon without material help from YouTube. And we have an evil gunman who had, through no fault of his own, lost all the parental figures in his life. The stories that are now being reported about the gunman in his earlier days, and his late mother’s attempt to set him straight, lend credence to the theory that she was the only restraint left on his actions. With her gone, there wasn’t anyone left who had enough authority to stop him.

In recent days, a potential school shooting in Everett, Washington, was foiled in its planning stages when the alleged planner’s grandmother turned him into police. In Parkland, Florida, only the police or the FBI could have stopped the gunman. And they did not. Whether they could have or not is going to be the question that will haunt us all for the days to come.