Until last month, the strongest evidence in drug and drunk driving cases in courtrooms across the nation often was a piece of paper - A crime lab or Breathalyzer report.
But a Supreme Court decision has sent a jolt through that procedure.
Now the prosecution must make a lab technician available to testify in person if the defendant demands it. As a result, some cases already have been dismissed. One state, Virginia, has called a special legislative session to change its laws. And some lawyers think the ruling will continue to have a major effect.
Read the full story in the LA Times.