Brandon “Tiny Doo” Duncan, the 33-year-old rapper from San Diego who may be facing life in prison because of his rap lyrics, entered a not guilty plea on Thursday (December 4).

Duncan is among several men who are being charged with what is known as gang conspiracy related to nine shootings that have taken place since April of last year. The law defines gang conspiracy as a time when a gang member "willfully promotes, furthers, or assists in any felonious criminal conduct by members of that gang,” according to the Los Angeles Times.

Some of Duncan’s codefendants are being charged based on their Facebook posts. Dana Greisen, chief of the DA's gang prosecution unit, recently explained how rap songs and social media statements can be dangerous, according to UT San Diego. Greisen said it's "another form of communication gang members use."

Tiny Doo’s lawyer Brian Watkins has said that while he does not deny Duncan's gang affiliation, his client’s work is no different from the raps written by Snoop Dogg or 50 Cent and that this case is about freedom of speech.

Watkins adds that injustice is at play here, according to the San Diego Fox affiliate.

"They’re charging Brandon Duncan with crimes that the District Attorney admits that he had no involvement in or even knowledge of,” he explains. "That is the definition of injustice.”

“It’s really given a black eye to the legal system here in the DA’s office,” Watkins added. “To charge someone with crimes while admitting he had no knowledge of those crimes. Based on his artistic expression, he made a rap album — a rap album that’s actually made in 2012, these shootings occurred in 2013 — so there’s absolutely no connection.”

Since Tiny Doo's case has become publicized, some Twitter users, including rapper Freddie Gibbs, have participated in the #FreeTinyDoo campaign.

Duncan’s trial is set for January 23.