Lyrics in a music video, posts on social media and ink on skin have brought gang conspiracy charges against two San Diego County men accused of benefiting from a string of gang-related murders, in a case that has drawn harsh criticism from civil liberties advocates.

Aaron Harvey, 26, and Brandon Duncan, 34, are among 15 people facing possible life sentences for allegedly benefiting from murders said to have been committed by members of the Lincoln Park Bloods in 2013.

On Monday their cases will go before a San Diego court, where a judge will review a request by the men’s lawyers to dismiss the charges.

Prosecutors argue that both men were members of the Lincoln Park Bloods. They allege that Duncan's music career got a boost from a series of gang slayings in 2013. For Harvey, authorities say he flashes Bloods gang signs in Facebook posts. Even the letters “CK,” tattooed on Harvey’s triceps, counts as evidence, as prosecutors say it stands for “Crip killer."

“They told me I was wanted for murder," Harvey told local San Diego NBC affiliate KNSD of his arrest in Las Vegas last year. "I'm walking out of my house one day and it's like the U.S. Army is outside waiting on me, with guns drawn, helicopters and assault rifles.”

His statements on social media and alleged references to his gang moniker, Baby Struck, by suspected gang members prompted San Diego authorities to include him in the prosecution of the group.

Duncan, also known as Tiny Doo, faces a similar charge of conspiracy over his rap lyrics. But prosecutors acknowledge that neither pulled the trigger in the 2013 crimes.

“The district attorney is basically prosecuting them for the content of their speech,” said David Loy, the legal director at the Southern California chapter of the American Civil Liberties Union, arguing that the charges violate Duncan and Harvey’s right to free speech under the First Amendment.

But the San Diego County prosecutor's office insists that it is in the right and that both men were members of the Lincoln Park Bloods — a charge Duncan and Harvey have denied.

“We believe if you join a group whose primary purpose is to shoot people in the adjacent neighborhood and promote and/or benefit from the shooting of the people in the adjacent neighborhood, that the members are responsible, even if we can’t show they all knew exactly when and who in that neighborhood would get shot,” the office told Al Jazeera.

Loy said he thinks prosecutors are “experimenting on this group of people, pushing the envelope as far as they think they can.” He also believes race plays a factor in the prosecution.

“I think it is part of overprosecution and overcriminalizing people of color,” he said. “I think they should only be prosecuting people they have good cases against, but they’ve definitely gone way too far in this case.”

Loy, who wrote a friend-of-the-court brief for Duncan, said that the district attorney was misinterpreting the meaning of section 182.5 of the penal code, the conspiracy statute. In the prosecutor’s interpretation, Loy said, a person can benefit from a crime without ever knowing about it or approving it.

“They're saying I benefited from these crimes, and they are saying my benefit is my stature went up,” Harvey told NBC. “I don't know how you can even measure stature or how can a person’s stature goes up. I didn’t even know I had stature.”

Although he talks about dealing cocaine, Duncan’s rap lyrics and social media posts are harmless, his lawyer Brian Watkins told The Los Angeles Times, adding that it amounts to the same kind of expression as that used by revered greats of West Coast rap. “It’s no different than Snoop Dogg or Tupac,” Watkins told the paper. “It’s telling the story of street life.”

Whether the charges against the men are dismissed may come down to a question of how “willfully” is interpreted as it was written and passed by voters in a referendum in 2000 in relation to section 182.5, Loy said.

The relevant statute reads that anyone “who willfully promotes, furthers, assists or benefits from any felonious criminal conduct by members of that gang is guilty of conspiracy to commit that felony.”

Here, Loy said, “willfully” modifies “benefits,” but the San Diego County attorney’s office doesn’t agree. The county’s interpretation “violates basic rules of grammar, not to mention criminal law,” he said.

But the San Diego prosecutor’s office said its interpretation of the statute is just keeping up with the times. “In the past, the use of the 182.5 statute was difficult because evidence had to come in the form of police officers telling a jury what they saw on the street as being gang promotion and membership, etc.,” the office said in a release.

“However, in the age of the Internet, investigators can collect thousands of social media pages and links of these defendants promoting the gang and demonstrating in no uncertain terms their gang membership. Prosecutors across the country routinely use this type of evidence to prove active gang membership.”

As for the issue of grammar in the law, the county couldn’t answer.

“That’s a complicated and specific legal discussion. You may want to check with a criminal law professor,” a county representative said.