Shooting I Know, But What's Tagging?

Caught this: At Prince of Peace, worshiper dies trying to stop tagger

...a parishioner checking on the food being set up in the parking lot saw something suspicious. A young woman was spraying graffiti on a church wall. When he asked her to stop, she knocked him to the ground...a man emerged from a nearby car and opened fire, killing Ordonez and wounding the other parishioner...recently gang members had threatened violence against residents who complain about or paint over graffiti...LAPD detectives are searching for the gunman and tagger but believe some witnesses are afraid to come forward out of concern about gang reprisals. Several witnesses talked to The LATimes only on the condition of anonymity, fearing for their safety.
 

Searching, I found this:

Some of the most common styles of graffiti have their own names. A "tag" is the most basic writing of an artist's name, it is simply a handstyle. A graffiti writer's tag is his or her personalized signature. Tagging is often the example given when opponents of graffiti refer to any acts of handstyle graffiti writing (it is by far the most common form of graffiti). Tags can contain subtle and sometimes cryptic messages, and might incorporate the artist's crew initials or other letters.
 

And this:

Tagging
	1. (VERB) THE ACT of performing simple graffiti using spray-paint (usually cheap) and stencils. Done quickly, usually in seconds. Usually during the day. For this you shoot to kill? ^