A court room filled with potential jurors were told to go home after gathering Tuesday for jury selection at the Yellowstone County Courthouse in Billings. They were informed that the triple homicide trial of Richard Covington was postponed due to the discovery of new evidence. Covington is charged with the murders of Patti Hubert, Norman Leighton and Gerald Morris.
The Office of County Attorney, Dennis Paxinos, announced the postponement. Court papers referred to DNA evidence. Covington’s attorneys agreed to the postponement.
On September 22, 2006, firefighters arrived at 211 S. 28th St., at apartment #3, Billings, in response to a structure fire and discovered the bodies of Hubert and Norman Leighton. A search warrant was later issued for the premises. The third body, of victim Gerald Morris, found at a separate location, had been shot.
Covington, 47, is currently serving a 40 year sentence for a robbery and stabbing.
DNA evidence provides a highly accurate form of proof that is commonly used in forensic cases. Some labs say it is accurate up to 99.9%. Other labs say DNA success is not best conveyed by such statistics that may give a wrong impression. I spoke with Carl Strayer, a technical service scientist, with a Ph.D. in molecular biology, at Promega, Madison, WI, (a company dealing in forensic services such as research kits for government agencies) explained that DNA testing discounts a large section of a population and tests and analysis vary. He stated that the more accurate the test and analysis, the more likely that other genetic types are discounted, so it is technically not a “match” as statistics may imply.
Strayer said that DNA testing has substantially evolved in the last 10-15 years. Old DNA techniques use less “markers” or genetic sites to be compared.
One of the early DNA tests used by many forensic labs included Restriction Fragment Length Polymorphism (RFLP) tests. RFLP required larger samples, for example, a larger amount of blood. Once that amount was tested and destroyed there was no further testing. Then, Polymerase Chain Reaction (PCR) tests became available. Smaller amounts of blood are used in PRC DNA testing. The sample is amplified and then labeled. The results are then analyzed.
PCR testing also evolved becoming more effective in technique and analysis. Some tests use 5-6 markers in each reaction that is repeated in short tandem repeats (STR) to compare in the genetic testing, others use 15-16 markers in each reaction. The results are amplified which creates greater accuracy. More “robust extractions”, or more efficient sampling, also increased accuracy. Strayer felt that the latest PCR DNA testing method is 1000 times more sensitive than the RFLP DNA testing method. Strayer said either method could be important if non-DNA methods of evidence are not sufficient such as a blood sample that is not unique or a lack of identifiable fingerprints.
There are various types of DNA testing and different forms may be more successful with some evidence that might otherwise be hard to test for human presence such as cigarette butts and envelope flaps. With the latest PCR testing, it is easier to find smaller presences of substances for testing and in a case where the bodies are burned, or there is possible smoke damage to samples, these techniques could be highly valuable.
Rod Souza and Scott Twito will prosecute the State’s case. Randi Hood and Matthew Wald will represent Covington. The trial has been rescheduled for February 8, with District Court Judge G. Todd Baugh presiding.