– Charis Kubrin might not seem like your typical fan of rap music.

A professor at the University of California-Irvine and a white, 45-year-old mother of one, Kubrin has a collection of hundreds of songs and CDs, ranging from gangsta rap to old-school hip-hop.

"This is one of my absolute faves," she said, holding up a copy of the Notorious B.I.G.'s "Life After Death."

For Kubrin, the appreciation goes beyond the music. As a criminology, law and society professor, she studies the perception of rap music in society and how a defendant's rap lyrics can be used as evidence against him in a criminal trial.

Kubrin said rap lyrics are stereotyped as violent, dangerous and threatening, while lyrics in other genres of music are viewed as artistic expression. The stereotype exists in courtrooms across the country, where prosecutors unfairly use rap lyrics as incriminating evidence against defendants, she said.

"Rap is another form of artistic expression, but rather than treating the lyrics as art and poetry, it's taken as literal and true," she said. "No other form of artistic expression has been treated by the courts this way."

Even Kubrin concedes she doesn't fit the mold of the typical fan. She garners snickers in the courtroom when she's introduced as an expert witness in rap music.

"The defendants have even laughed at me," she said with a chuckle.

Through her research, she hopes to help change the perception of rap music, especially in the courtroom. She has written three research papers on the topic, including one titled "Rap on Trial," and has published op-ed articles in the Los Angeles Times and New York Times. She also regularly consults with defense attorneys and has testified as an expert witness on how rap lyrics are a form of creative expression.

In December, Kubrin joined forces with rap star Killer Mike in writing an amicus brief urging the Supreme Court to hear the case of former Mississippi high school student Taylor Bell, who was suspended in 2011 after he wrote a profanity-filled rap that decried two coaches accused of sexual misconduct.

In the brief, signed by big-name rap artists including T.I., Big Boi and Pharoahe Monch, Kubrin says Bell's lyrics are protected under the First Amendment. "The Government punished a young man for his art — and, more disturbing, for the musical genre by which he chose to express himself," the brief says.

Kubrin has been in love with rap ever since she first heard "The Message" by Grandmaster Flash when she was 12.

"I was just entranced by the storytelling," she said. "It was so different from the life I was experiencing."

While attending Smith College, a women's liberal arts school in Massachusetts, she said she hid her love of rap music from her feminist friends who thought the lyrics were misogynistic.

As a sociologist at George Washington University, Kubrin began studying rap as an important voice for a historically marginalized group of people. While the music has been criticized for its violence and misogyny, Kubrin said rap is a form of poetry that should be understood in its historical and social context.

"It's shouldn't be taken as literal. It's not an autobiographical account," she said, adding that violent lyrics can be heard in other genres as well. Johnny Cash never shot a man in Reno just to watch him die, she notes. Bob Marley didn't actually shoot the sheriff.

Kubrin said she loves to play rap while driving in the car, but she has scaled back now that her 5-year-old son is beginning to understand the lyrics. She admits that her husband, a physics professor, is somewhat baffled by her musical taste.