I would like to know what exactly is an art. Can we consider an act of murdering without getting caught as an art? Can we consider an act of inflaming the crowd or mob for mass destruction an art? Then can criminals also be called artists? I want to know what is the length & breadth of the art. When any act becomes an art? What is the criteria?
Art is a vague term without definite boundaries. People use the term for many things, including representing something meaningful in some way or a sophisticated thoughtful way of doing something. Some people believe it requires some sort of developed skill to create something sensually stimulating with the intent of being art, although others can disagree about its status as art and its quality based on personal preferences. Usually, it is a set of stimuli for the intent of evoking some kind of reaction, pleasant, meaningful, or something else. Although it is also used to describe an application of skills. For example, some say psychotherapy is some science but also an art form when it is done well.
If the average unskilled person can easily do it and it isn't anything original or interesting, it probably wouldn't be considered art by very many (e.g., destructive or criminal activities).
We may have two main approaches to the philosophical definition of Art:
A more "traditional" one, aimed at find the essence of Art, i.e. a property (or a limited collection of properties or features) able to characterize univocally artworks.
Following this approach, we cannot have too broad a characterization, that applies to all human "artifacts" or activities (e.g. crime).
Artworks may have at least expressive and formal properties, but a definition based on these "minimal" criteria must consider e.g. human faces and gestures, that have expressive properties without being works of art, as well as natural objects that have formal properties but are not artworks.
A different approach is based on the Wittgensteininan concept of family resemblance (German: Familienähnlichkeit):
"things which could be thought to be connected by one essential common feature may in fact be connected by a series of overlapping similarities, where no one feature is common to all of the things."
According to this approach, we cannot aim at a definition that "pick up" the essence of Art; the phenomena of art are, by their nature, too diverse to admit of the unification that a satisfactory definition must impose on them.
Well, if it is art, then it's "performance art", https://en.wikipedia.org/wiki/Performance_art. And indeed, one of https://en.wikipedia.org/wiki/Guillermo_G%C3%B3mez-Pe%C3%B1a performances involved biting the head off a live chicken. That, however, was in the context of making a multi-cultural point, not violence/criminality for its own sake (at least I don't think so).
Now, if your question follows on the heels of https://www.nytimes.com/2017/10/02/us/las-vegas-shooting.html, then I don't think you'll get much sympathy. Maybe when that moron shot himself, >>that<< was a "performance".
But a much better case for "suicide as performance" is https://en.wikipedia.org/wiki/Mohamed_Bouazizi who set himself on fire, thus starting the entire Arab Spring movement. Hard to imagine a performance with more significant consequences.
So if "suicide as performance" can somehow be argued, then "murder as performance" is just the next step down that slippery slope. And I imagine ISIS/terrorists would argue taking such steps. They might say that they're just like Guillermo Gómez-Peña writ large, in a manner of speaking.