Murphy freezes the image, then rewinds it. The girl goes through the motions in reverse, hopping down, backing away. Murphy does this repeatedly, forwarding, reversing, forwarding again, as if willing the sequence to change. It doesn't. The girl makes the same bad decision each time.

It is not yet 10 a.m., the beginning of the school day at Media Arts Academy, a charter school in Hawthorne that calls itself Hip Hop High and exemplifies, in some ways, the promise and the challenges of the charter school movement.

It is a place where failing students get a second chance. Media Arts showers them with attention, treats them with respect, offers plenty of independence and, along the way, gives them the opportunity to lay down their own hip-hop beats and raps.

Some days, it all works beautifully. Today is not going to be one of those days.

Murphy minimizes the video image, which was recorded earlier that morning. She stands, a tall, striking woman whose long red hair glides down the back of a black leather jacket. An ankle tattoo is visible.

Behind her is a cabinet, which has been rifled. Cash has been taken. The girl on the surveillance tape is the sole suspect.

"I'm going to have to talk to her," Murphy says.

I am really friendly

I wonder if I'll make it to my 40s.

I hear gunshots

I see myself lying on the floor

I want world peace

-- Maria Olmedo

12th grade

Media Arts was founded in 2004 and endured a couple of years of dreadful academic performance before turning a corner last year under Murphy's leadership. Its Academic Performance Index score shot in one year from 386 -- about as low as a school can go -- to 537.

That is still extremely low, more than 150 points below the state average and 15 points below nearby Leuzinger High School, a regular public school in Lawndale. Not a single student at Media Arts scored at the advanced level in any subject included in state standardized tests. In math, not one was even judged proficient.

On the plus side, few schools have achieved such strong growth in a single year.

This year, Media Arts formed an alliance with a Minnesota school, the High School for Recording Arts, founded in 1996 by rapper David "TC" Ellis, whose career was nurtured by the rock star Prince. The idea, he said, was to provide "experiential education" built around something that urban kids loved, hip-hop music. Now Media Arts is using some of Ellis' ideas to motivate students through music.