Patrick Barnes, a pediatric radiologist at Stanford University, was a key prosecution witness in the trial, but in 2011, said he would not give the same testimony today. He said there had been a revolution in the understanding of head injuries in the past decade, partly due to advances in MRI brain scanning technology: "We started realizing there were a number of medical conditions that can affect a baby's brain and look like the findings that we used to attribute to shaken baby syndrome or child abuse", such as infections and in utero strokes.