After another mass shooting in a school, Americans are seeking to solve the problem of gun violence.
Nikolas Cruz has been charged with 17 counts of murder after a shooting at his old school, where he had been expelled for "disciplinary reasons".
Fourteen more were wounded at Marjory Stoneman Douglas High School in Parkland, Florida, in one of the worst mass shootings in modern American history.
Cruz's name now joins a roll call of mostly white men attached to the atrocities.
Of 95 mass shootings carried out in the US between 1982 and 2017, 92 of the perpetrators were male.
The final three are made up of two women, and one case of one man and a woman working together, in the San Bernardino attack in December 2015.
The shootings broken down by race, by Statista, show that 54 of the gunmen were white, 16 black, and seven each Latino or Asian.
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Although there is frequent speculation about the mental health concerns of those who carry out the devastating acts, there is less conversation around whether the gender of the perpetrator is a larger issue.
Professor David Wilson, a criminologist at Birmingham City University, said: "Characteristics of USA school shooters? Male; used legally owned firearms – usually semi-automatic weapons; were ex students of the school they targeted."
He told Sky News: "What is interesting is that the average gunman tends to be slightly older than we have here [in Florida].
"If you look at the motivation that we know about it does seem to be that men handle their catastrophic loss and self esteem worse than women.
"When the husband or father loses their job or goes through a divorce separation they are thrown out of the home.
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"Their status is tied up in their occupation so they seem to suffer more psychologically, which seems to propel them in that way.
"Men also have unequal access to guns and training in using weapons like handguns and rifles.
"Three-quarters of mass murders will use firearms and so that unequal access to the training is relevant."
Professor Wilson added that men tend to have fewer support networks outside the family unit and their workplace, which can be problematic if one of those breaks down.
He said: "Men all over the world have these experiences, but they don't carry out mass murders.
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"The reason is that we have different gun laws.
"In Florida, we have reports of the gunman's adoption and his depression, but that is an abstraction.
"It is not the lack of provision of mental health services in the US, but the availability of guns."
Some of the worst mass shootings in schools in recent years include the Sandy Hook massacre and the Isla Vista shooting.
Elliot Rodger killed six people and injured 14 others before shooting himself dead inside his car on the Isla Vista campus in California in 2014.
Adam Lanza, 20, stole his mother's guns after shooting and killing her at their home in Newtown, Connecticut on 14 December 2012.
He drove her car to Sandy Hook Elementary School, where he went as a child.
He killed 20 children, six adults and himself within 11 minutes.
Eric Harris and Dylan Klebold attacked Columbine High School in Colorado on 20 April 1999.
They murdered 12 students and one teacher and planted more than 100 explosive devices around the school.
They exchanged fire with police officers at the scene before shooting and killing themselves.
According to the Pew Research Centre, women who own a gun are more likely to have purchased it in later life, and more likely to say protection is the only reason they have it, not just one of the reasons for it.
The centre's research also indicates that Republican and Republican-leaning women are more likely to support stricter gun laws, particularly around selling to those with mental health issues and the availability of assault weapons, compared to men with the same political leaning.
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James Alan Fox, a criminologist at Northeastern University, told CNN: "Women tend to see violence as a last resort, as a self-defence mechanism. You use violence if you have to, if there's no other way out.
"Men tend to use violence as an offensive weapon, to show them who's boss."
He added that men were more likely to own guns, and be more comfortable around them.
Mass shootings have followed a pattern in recent years when carried out by a man, which tends to focus around threats to their masculinity.
There have been suggestions that Cruz was heartbroken after breaking up with a girlfriend, and had got into a fight with her new boyfriend.
Stephen Paddock, who killed himself after opening fire from his hotel room over a concert in Las Vegas in October, did have a girlfriend, but was known as a "loner".
She said he had grown distant in the final years of their relationship.
Omar Mateen, who carried out the shooting inside an Orlando nightclub, had been described as "mentally unstable" by his ex-wife, who made claims of abuse during their marriage.
The only recent shooting to involve a man and a woman was carried out in San Bernardino in December 2015, when husband and wife Syed Farook and Tashfeen Malik opening fire at an Inland Regional Centre.
Although there were indications both of them had been radicalised to some extent, Farook was also understood to have workplace grievances.
More from Florida
Although some experts disagree on what is classed as a mass shooting, after the 2012 Sandy Hook massacre Congress defined it as a single incident where three or more homicides took place.
This was done to enable states to ask the attorney general to intervene and investigate. In criminology terms, it relates to four homicides or more in a single incident.
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Sky News
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