Its allegedly rosy ratings for mortgaged backed securities understated the severity of the growing housing crash and may have actually contributed to the financial crisis. Michael de la Merced has been following the story reporter for our partner, The New York Times.

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For some people watching the pre-trial hearings in the case of Khalid Sheik Mohammed, the alleged mastermind of the September 11 attacks, there was a simple question: Is that man responsible for the death of my loved one?

The New York City Medical Examiner has announced that the office is reviewing more than 800 rape kits, cases were handled by a former lab technician who made a series of incorrect reports over the course of ten years, from 2001 to 2011. Lawrence Kobilinsky, forensic scientist and chair of the science department at John Jay College, discusses the science of DNA analysis. Erin Murphy, professor of at New York University School of Law, explains the legal issues at stake.

It's been 150 years since the signing of the Emancipation Proclamation. Historian and novelist A.J. Verdelle talks about what this meant for the millions who were freed. 

In 1993, teenagers Damien Echols, Jason Baldwin, and Jessie Misskelley, Jr.—known as the West Memphis Three—were convicted of the murders of three eight-year-old boys in Arkansas after a trial marked by tampered evidence, false testimony, and public hysteria. Baldwin and Misskelley were sentenced to life in prison, and Echols was sentenced to death. Over the next two decades, thousands of supporters called for a new trial, and in a shocking turn of events, all three men were released in August 2011. Echols shares his story in his book Life After Death.

Filmmaker Joe Berlinger was on the show in October 2011 discussing his three documentaries on the West Memphis Three. Listen to that interview.

Errol Morris has been investigating one of the most notorious and mysterious murder cases of the 20th century, the case of Jeffrey MacDonald, a Green Beret doctor. He was accused and convicted of murdering his pregnant wife and young daughters in Fort Bragg, North Carolina, in 1970. Morris’s new book A Wilderness of Error: The Trials of Jeffrey MacDonald shows us that almost everything we have been told about the case is deeply unreliable. It’s a careful, thorough investigation that looks at the myth surrounding these murders, and is a meditation on truth and justice.

The controversial Racial Justice Act in North Carolina could be repealed later this week. Neil Vidmar, a professor at Duke Law School, discusses what happens when racial bias and statistical evidence collide. 

In the wake of the September 11 terrorist attacks, the Bush Administration authorized the National Security Agency to eavesdrop on American citizens and others without a warrant. Congress officially legalized this once-secret program with the passage of the 2008 amendments to the Foreign Intelligence Surveillance Act, but civil libertarians claim that warrantless wiretapping is unconstitutional. The Supreme Court has just agreed to hear a case on this very issue. Adam Liptak, Supreme Court correspondent for our partner The New York Times, explains what's at stake.

The case of Tyler Clementi became national news when the Rutgers University freshman jumped off the George Washington Bridge in September, 2010. Clementi had recently told his family he was gay. Last March, a New Jersey jury convicted Clementi’s roommate, Dharun Ravi, of bias intimidation and invasion of privacy, after Ravi spied on Tyler kissing another man. Today, New Jersey Superior Court Judge Glenn Berman will announce Ravi's sentence, and many are concerned that he might face a punishment that doesn’t fit the crime. Marc Pourier, law professor at Seton Hall University, is particularly concerned that Ravi will face an unfair sentence. 

On February 4, 1983, Wanda Lopez was stabbed to death in a Texas gas station. A jury convicted Carlos Deluna for the murder five months later and Deluna was executed in December 1989. But this week, nearly 30 years after Wanda Lopez’s death, a new investigation into Deluna’s conviction and execution poses serious questions about Deluna’s guilt, and challenges the fairness of our justice system.

James Goldston, head of the Open Society Justice Initiative, talks about arguing a landmark court case in front of The European Court of Human Rights in May. Khaled El-Masry, a German citizen, alleges that he was abducted in Macedonia in 2004, flown to Afghanistan, interrogated there and then later released in Albania. It’s the first case to be heard about alleged abuses arising from the CIA’s policy of extraordinary rendition.

Could all the public attention affect George Zimmerman’s right to a fair trial? It’s a question that Wendy Kaminer has been mulling over. Kaminer is a lawyer, social critic, and correspondent at The Atlantic. She’s also the author of eight books, including “Worst Instincts: Cowardice, Conformity, and the ACLU.”

Last night in a press conference, Florida state special prosecutor Angela Corey announced the charges filed against George Zimmerman for the shooting death of Trayvon Martin on February 26. Zimmerman was arrested yesterday on charges of second degree murder. Adam Kaeloha Causey, a reporter with the Florida Times Union, attended last night's press conference. Dale Carson is a lawyer and retired legal instructor for the FBI, and joins us to discuss the legal explanation behind Zimmerman's arrest.

By now, most of us have heard of Trayvon Martin, the 17-year-old African-American boy who was shot and killed while walking through a friend’s gated community in Sanford, Florida. The shooter was George Zimmerman, a neighborhood watchman who is not black, and who thought Martin looked suspicious. Martin had no weapons on him — only a bag of Skittles and a can of iced tea.

When a violent crime is committed and reported, it's expected that investigators will collect evidence, process it, and use that evidence to track down the perpetrator. But in tens of thousands of rape cases, that is not what happens. Instead, the evidence collected is shelved and left unprocessed for years. In many cases, the rape kits are stored incorrectly so that contamination is likely to occur. In other cases, the kits have even been deliberately destroyed by the police.

In places like Los Angeles and New York, efforts have been made to change this. And now Detroit and Houston are taking steps to do the same.

The country's "toughest sheriff" has had his gold star revoked. A scathing U.S. Justice Department report released Thursday found that Maricopa County Sheriff Joe Arpaio's office carried out a blatant pattern of discrimination against Latinos and held a "systematic disregard" for the Constitution amid a series of immigration crackdowns that have turned the lawman into a prominent national political figure.

In a small town in Texas, two young men knock on the door of a woman’s house as she's making cookies. They ask to use her phone. But as her back is turned, they kill her and then two other innocent bystanders all so they can enjoy a brief joyride in her car. In the end, one murderer is sentenced to life in prison. The other is given the death penalty.

After four years in prison, Amanda Knox walked free on Monday. The 24-year-old American woman, and her former boyfriend, Raffaele Sollecito, were convicted of murdering her roommate, Meredith Kercher in 2009. Sollecito's conviction was also overturned by an Italian appeals court in Perugia. The story of sex, drug-using, exchange students, and murder became a media sensation around the world. The prosecution's case against Knox was derided as based on circumstantial evidence doubted by independent experts.