Homicide
Homicide refers to one human being killing another.[1] Homicides can be divided into many overlapping types, including murder, manslaughter, justifiable homicide, killing in war, euthanasia, and capital punishment, depending on the circumstances of the death. These different types of homicides are often treated very differently in human societies; some are considered crimes, while others are permitted or even ordered by the legal system.
https://en.m.wikipedia.org/wiki/Homicide
Murder
Murder is the unlawful killing of another human without justification or valid excuse, especially the unlawful killing of another human being with malice aforethought.[1][2][3] This state of mind may, depending upon the jurisdiction, distinguish murder from other forms of unlawful homicide, such as manslaughter. Manslaughter is a killing committed in the absence of malice, brought about by reasonable provocation, or diminished capacity. Involuntary manslaughter, where it is recognized, is a killing that lacks all but the most attenuated guilty intent (mens rea), recklessness.
https://en.m.wikipedia.org/wiki/Murder
You can legally kill a person in self defense in Florida and it would be considered a homicide but not a murder. The stand your ground law might have encouraged more people to obtain a concealed weapons permit and carry a weapon for self defense. Over 1,000,000 Florida
residents have concealed carry permits.
Concealed carry gun permits spike after Pulse shooting
July 15, 2016
Thousands of Floridians are looking to take personal safety into their own hands after the massacre at an Orlando nightclub last month.
In May, the Florida Department of Agriculture distributed more than 20,000 applications to people interested in a concealed weapon permit or other firearm license. That number jumped to more than 36,000 in June, according to recently released numbers.
***snip***
On average, about 180,000 new applications are turned in each year and fewer than 4,000 are denied, according to records from the past five years.
By the end of June, more than 1.5 million people were licensed to carry a concealed weapon in Florida.
Local gun safety instructors said they expect the interest to continue growing during the next few months, fitting a trend seen after most mass casualty incidents in the U.S.
http://www.orlandosentinel.com/news/pulse-orlando-nightclub-shooting/os-orlando-shooting-concealed-carry-20160707-story.html
Obviously when more people are legally carrying guns there will be more instances where a gun is used for legal self defense. A percentage of those will result in the death of an attacker or a homicide. That may not necessarily be a bad thing although any loss of life is tragic. Innocent people may have be able to survive an attack without serious injury or ending up in a grave.