Confirming Guilt or Innocence and New Planets
CHAPTER 69 New Planets and Innocence
Evolution is a topic I've often discussed in these columns over the years. Recently, one of our Old Guard members gave two lectures tracing the history of evolutionary thinking from well before Darwin down to evolution happening before our very eyes today. He covered randomly occurring mutations in DNA and the rapid evolution of bacteria to resist antibiotics and the resulting problems with MRSA and other diseases.
Speaking of DNA, every few weeks there's a story in the media about a convicted killer being set free after years of imprisonment based on DNA evidence showing him to be innocent of the crime. The March 11, 2016 issue of Science has a section devoted to forensics and the roles various types of evidence play in criminal investigations. In one article, Kelley Servick discusses the reliability of using "pattern evidence" to convict crime suspects. Pattern evidence includes such things as fingerprints, bite marks, tire tracks and indentations on cartridge casings of bullets fired at the crime scene. In 2009, a committee of the National Academy of Sciences concluded that none of these techniques had been shown to be reliable enough to consistently establish a connection between the evidence and a particular individual or source. Microscopic comparisons of hair samples also fell into this category.
One problem with these types of pattern evidence is the inability to come up with a statistical probability of a connection between the item and the suspect. I had thought that fingerprints were pretty solid evidence tying a suspect to a crime but the article cited a study involving over a hundred different fingerprint examiners. The examiners came up with 7.5% false negatives, where they misidentified pairs of prints belonging to the same person as being from different persons, and 0.1% false positives where two prints were incorrectly identified as being from the same source. Months later, the same examiners only came up with the same answers some 90% of the time. Not a very good result if you're going to send a person to prison for life based on this type of evidence!
With DNA, the case is different. Depending on how many of the huge number of base pairs are analyzed, a match with DNA at the scene of the crime or on the body of a victim can be statistically calculated with precision which may result in odds of millions to one in favor of a match. Hence all those convicts you see being released after years of unjustified servitude. With all the improvements in sensitivity it is now possible to detect and analyze truly minute bits of DNA. DNA can be sampled from a fingerprint these days. This certainly is a boon to forensics. Or is it?
In the same issue of Science, there's an article by Douglas Starr titled "When DNA is Lying". The article deals mainly with the work of biologist Greg Hampikian of Boise State University in Idaho. Hampikian holds joint appointments at BSU in biology and criminal justice and heads the Idaho Innocence Project. A large number of those convicts we see released from prison owe their release to such innocence projects. Hampikian hasn't confined his efforts to Idaho. He was involved in the freeing of Amanda Knox and her Italian boyfriend, who were convicted of murder in the headline-making case in Perugia, Italy back in 2007.
A local fellow was convicted of sexual assault and the murder of the female victim, who was Knox's housemate. The evidence against the fellow was overwhelming. However, DNA from Knox's boyfriend was found on the bra clasp of the victim. In addition, a knife in Knox's kitchen was found to have her DNA on the handle, expected since she used the knife for cooking; however, a trace of the victim's DNA was found on the blade of the knife. Based on this DNA evidence, Knox and her boyfriend were convicted of being complicit in the murder and spent four years in jail, were reconvicted. However, they were finally released after being declared innocent by an Italian high court after a review of the DNA evidence.
The review of the evidence involved input from Hampikian and his team. The essence of their input was that the bra and knife were mishandled by the police in their investigation. For example, the bra clasp had been passed around among the investigators and even placed on the floor for a photograph of its original position. The amount of the victim's DNA on the knife blade was miniscule and could also have come about in mishandling the blade. The high court finally agreed with this possibility. Hampikian and his colleagues had run experiments in Idaho in which they showed how DNA can be transferred by handling a knife. Indeed, on their knife they had found DNA of a dean who hadn't even been in the room where they carried out their experiments!
I certainly don't know if the final verdict in this case was correct or not but, as I was writing this column, I found in the latest June issue of Scientific American an article by Peter Andrey Smith titled "When DNA Implicates the Innocent". There is no doubt that the homeless Lukis Anderson did not, as charged, murder Silicon Valley multimillionaire Raveesh Kumra back in 2012. The charge, which carried the death penalty, was made based on the basis of Anderson's DNA being found at the crime scene. The only problem was his alibi. At the time of the murder he was drunk and hospitalized under constant medical supervision! Case closed. How did his DNA get on the victim? The same paramedics who had treated Anderson earlier that day of the murder had carried his DNA on their mission to attend the murder victim, planting Anderson's DNA at the crime scene. There's still plenty of room for old fashioned police work, even with DNA!
Well, so much for evolution and DNA. Anybody who has followed these columns over the years will know of my obsession with anything related to space and the universe. Obviously, I cannot ignore the announcement in May that NASA's Kepler planet-hunting mission has come up with not just a few new confirmed planets, but an astounding 1284 of them! It seems that there is more sophisticated software that permits the researchers to separate out signal from noise and the increased precision has also allowed them to detect a few new possible Earth-like planets. There are now about nine such planets that have been detected. Of particular interest is one planet, Kepler -452b, which not only is in a habitable zone but also has an Earth-like year of 385 days! NASA requires detection of three orbits of its star for a planet to be "confirmed". That means Kepler-452b couldn't be confirmed unless more than three of our years have passed. Incidentally, "confirmed" means NASA is 99 percent sure the object is a planet, a high standard indeed. There are still some 3,000 more possible candidates for confirmation as planets in the Kepler data.
Let's take a look back at one of our own solar system's planets, good old Mars. On the Discover magazine Web site, an article by John Wentz on May 19 titled "Ancient Mars Was Wet and Wild" caught my attention. The article cites recent work by Alexis Rodriguez and coworkers at the Planetary Science Institute interpreting data from various Mars orbiters. It's hard to imagine, but the conclusion from looking at a 30 kilometer wide impact scar and water erosion features on Mars is that some 3.4 billion years ago, a giant asteroid hit Mars and caused a tsunami with waves hundreds of feet high that smashed into the ground tossing around rocks and boulders and leaving its mark on Mars' surface.
Less than 20 million years later another asteroid clobbered Mars but by this time Mars was colder and part of the ocean was frozen. The water was also much saltier than it was during the first asteroid impact and when the second asteroid hit, the frozen or nearly frozen brackish waves froze in place instead of washing back. The researchers propose that these waves froze in place and are still there on Mars, buried under the surface. This I find hard to believe. We obviously need a Mars rover that can search out and drill down really deep to see if those waves really are there today. Doesn't sound like the water would be fit to drink, however.
Finally, as I'm finishing this column on Memorial Day, I will take up my copy of "Heroes Among Us", a 388-page book by John Ent published in 2004. I've probably mentioned in past years that John and I and other youngsters in Mechanicsburg, Pennsylvania played baseball on a field across from his house. His book is a memorial tribute to those Mechanicsburg High School students/graduates who fought in World War II. (John himself spent 31 years in the U.S. Army Infantry and served in combat in the Korean and Vietnam Wars.) Mechanicsburg had a population of under 6,000 in those days and the book lists 30 who attended the high school who perished in the war. Here, I salute the two I knew best, William Guyer, who lived across the street and Ernest Martin, who lived just a few doors down the street from our rented house. Bill, a gunner and radioman on a B-25 bomber, died in a plane crash on a supply mission in New Guinea. Ernie was in the infantry and was killed in action in France. Sadly, none of those 30 heroes lived to become christened members of the "the greatest generation".
Next column, hopefully, on or about July 1.
Allen F. Bortrum