Tomorrow morning, the trial of Antwain Steward for a 2007 double murder will begin in a Newport News, Va.,  courtroom (it was continued today because of a sick witness). Most homicide cases do not raise significant cultural issues. Steward was charged in the 2007 shooting deaths of Brian Dean and Christopher Horton. The case had gone cold, but detectives decided that the lyrics to a song Steward released under his stage name, Twain Gotti, constituted a confession to the crime.

Beats headphones made by Beats Electronics are seen on display in Los Angeles,CA on May 9, 2014. Tech giant Apple is reportedly close to purchasing the audio equipment maker and music-streaming service co-founded by rap artist Dr Dre. In a deal that could be worth some 3.2 billion USD, Dr. Dre is poised to become the first billionaire hip-hop artist. AFP PHOTO / ROBYN BECKROBYN BECK/AFP/Getty Images Beats headphones (Robyn Beck/Agence France-Presse via Getty Images)

That turn of events might sound improbable. But Erik Nielson, a professor of liberal arts at the University of Richmond who studies the relationship between law enforcement and African American culture and who is preparing to testify as an expert witness in Steward’s trial later this week, says the case is part of a larger trend. Since the 1990s, prosecutors have increasingly used rap lyrics, even those with tenuous connections to actual crimes, as either evidence of premeditation or confessions, using songs as leverage in everything from indictment proceedings to plea-bargain negotiations.

This development says a great deal about the evolution of law enforcement tactics. But the treatment of hip-hop, particularly the subgenre of gangsta rap, with suspicion also suggests something about rap’s position in popular culture. Jay Z socializes with President Obama, and Kanye West’s upcoming wedding to reality television personality Kim Kardashian is dominating tabloid covers. But even as rappers have become beloved mainstream figures, the music they make gets treated as if it is literally dangerous.

Nielson acknowledges that it is difficult to acknowledge just how often police and prosecutors invoke rap lyrics, because songs can be used in proceedings that are later sealed, including indictments. But he says he has seen at least 20 cases in the last several years. Given the challenges of ascertaining the full extent of the tactic, those figures mean “we’re talking big numbers,” Nielson says.

Nielson points to California as the origin of this trial strategy, citing the state’s size and aggressive approach to gang-related cases. “I hesitate to call them creative because that sounds complimentary,” he says.

The New York Times, in a piece about the Steward case, pointed to a 2006 edition of the U.S. Attorneys’ Bulletin devoted to hip-hop and gangs. In a piece in the briefing, Donald Lyddane, an intelligence analyst in the Federal Bureau of Investigation’s Safe Streets and Gang Unit, laid out ideas for how prosecutors could turn music to their advantage.

“It is equally important to recognize that the lyrics demonstrate that the gangster lifestyle has become mainstream,” he wrote. “Do all gang members write graffiti, get gang tattoos, or compose true life proclamations in the form of hip-hop lyrics? No. A significant number of gang members do, however, to the point where investigators and prosecutors must take advantage of such behaviors. . . . The contents of these writings frequently reflect the author’s gang mentality and, in some cases, result in solid investigative leads. Occasionally, the writings can be used as evidence.”

Whether the lyrics in Steward’s trial represent a “solid investigative lead,” much less a confession, seems a matter of debate. The description of a murder in “Ride Out,” the song that is being taken as a confession, seems obviously hyperbolic, referencing weapons and means of violence that were not employed in the homicides in question. When Steward raps that “Everybody saw when I m———– choked him / But nobody saw when I m———– smoked him / Roped him, sharpened up the shank then I poked him / 357 Smith & Wesson mean scoped him, roped him,” it sounds more like he is describing an attempt to kill an adversary with a Rasputin-like resilience than an actual person.

But even though prosecutors are supposed to find material connections between rap lyrics and crimes, judges have discretion as to what is admissible, Nielson explains. And differing levels of familiarity with genre conventions may make certain lyrics appear more unique and threatening than they are.

“What is clearly not a connection for me may be a connection for someone else,” he says. “If someone was shot to the head with a Glock, if you are a judge who knows nothing about rap music and a prosecutor says, ‘Your honor, we have a victim who was shot with a Glock, and in this kid’s lyrics, he talks about putting one to the dome with a Glock 9 mm.’ I can find you a million songs that reference Glocks or AKs. That’s the point. It’s a genre convention.”

As jury pools increasingly contain people who grew up with hip-hop, defendants may have a greater chance of facing peers who actually understand the genre’s artistic intentions, Nielson says. But not everyone gets that rappers have both real and fictional personas or that their artistic credibility relies on whether or not they meet “authenticity requirements” that can be fulfilled by local references and use of particular locations in videos or by real-life associations with violence. That gap creates room for prosecutors.

“Rap itself really does prime these stereotypes about young men of color. When juries hear this violence and misogyny and drug dealing, all of this sort of comports with some people’s stereotypes about these people anyway,” Nielson says. “They’re guilty of something.”

Nielson points out that changes in social media and music distribution that are critically important for indie artists have made it far easier to for law enforcement officials to track down videos, audio recordings and transcriptions of lyrics.

“Social media has been a really important and valuable tool for amateur artists who are trying to distribute their music outside of increasingly narrow mainstream channels. So they’re flocking to it and it’s become very effective,” Nielson says. “The problem is that it’s being monitored and it’s easy to monitor. It’s solving a problem for rappers on one hand, but it’s creating a problem for them on the other.”

But sometimes the music they find is not the creation of the person performing it. Last year, Nielson testified in a trial involving a 14-year-old. The prosecution in the case attributed written and spoken lyrics to the defendant, but when Nielson went digging through obscure videos from Chicano rappers, he found out the boy was just repeating lines from some of his favorite tracks.

And misattribution of lyrics is not the only risk. The use of rap lyrics in prosecutions comes at a moment of vigorous debate about whether online comments are tied to intent. That question shows up in conversations about everything from the Internet-based harassment of female writers to whether rap lyrics posted on Facebook constitute a specific threat. A group of college-based First Amendment legal clinics has asked the U.S. Supreme Court to take on U.S. v. Elonis, involving a conviction based on the idea that such lyrics constituted a “true threat,” which are not a protected category of speech.

Where might it be reasonable to draw the line between “true threats” and artistic expression, lines that get blurred not only in rap but in genres such as narcocorridos, which draw some of their power from their references to real events?

That question, Nielson says, “is the reason I resist using it as evidence. The fact that you have to ask where do you find the truth in something like this, even if there may be some truth in some of the lyrics. It’s inherently fictional. It’s told in rhymed verse. Word choice isn’t always dictated by your desire to communicate a message. . . . We also know that in gangsta rap that the stuff least likely to be true is the stuff most likely to be used against these guys in court. If rappers killed everybody they said they killed or that they wanted to kill, there’d be nobody left.”