Traditionally, search warrants only went one direction. A crime was committed or suspected, and the police would investigate. Witnesses would be contacted. A theory would be developed. When the police had probable cause to search for evidence, they got a search warrant and searched.
Over the last year, the nonprofit investigative newsroom ProPublica has published a series of articles that called into question whether some forensic techniques produce reliable results. One of the techniques questioned is the matching of wear marks along the seams of blue jeans. Now, a leading forensic image analyst and a postdoctoral researcher have published a study finding that the technique produces limited evidence at best.
In 2009, the National Research Council issued a report on forensic analysis in court. It found that few forensic investigative techniques are supported by sufficient science.
When a criminal defendant's fingerprints are at issue, the stakes are high. The person has been accused of a crime, and those fingerprints could theoretically place them at the crime scene or otherwise indicate their involvement. People go to prison in cases where a matching fingerprint is the primary evidence.
Have you ever wondered if the government is monitoring your Facebook or Instagram? They are.
About a million people each year are arrested for drunk driving in the United States. When you're pulled over on suspicion of OWI, you will be asked to blow into a breathalyzer.
In 2018, a Mexican immigrant who had been brought to the U.S. as a teenager was convicted in Iowa of intent to deliver marijuana. During a 2017 traffic stop, officers allegedly found 184 one-pound bags of marijuana and a handgun in his car. Although he claimed he had been using the marijuana to treat back pain, Guillermo A. pled guilty to the charge.
Prosecutors have a legal and ethical duty not to knowingly allow perjury. If a prosecutor learns that a witness -- even a police officer -- in one of their cases lied on the stand, that prosecutor is required to notify the judge and attempt to correct the matter.
It's a tale as old as time. Someone is arrested and held in jail before trial. Naturally, they're desperate for a friendly face or a caring voice. They spill their guts to their new friend, giving details of the crime. That "friend" contacts the prosecution offering to turn over those details in exchange for a break on their own sentence.
In many criminal cases, the police rely on the testimony of an eyewitness to the crime. Eyewitnesses may have crucial information about what happened, of course. They are also frequently used to identify a suspect. These identifications are typically done by having the eyewitness look at a lineup or an array of photographs.