He said that he believes they WILL catch the killer, and that trace evidence is not as important as just plain following up on all clues.
However, as far as trace evidence is concerned, he mentioned the earlier report that the skull had been injured, and said that it could be an important clue. He said that, after all, they were able to identify the remains of the Romanovs 75 years after they were murdered.
I'll bet that was Dr. Michal Baden...he's tops in the field:
"Michael Baden, M. D. interprets the dead. He pays attention to the nuances of bruises and abrasions in ways that few people can. As a leading forensic pathologist of international renownand one of only about three hundred fulltime forensic pathologists in the country---during his forty-year career he has conducted more than 20,000 autopsies. From 1960 until 1985 he was New York City's medical examiner (ME) and he is currently co-director for the Medicolegal Investigative Unit of the New York State Police. That means he's available 24/7 for consultations, autopsies, and evidence interpretation.
Most people who pay attention to high-profile criminal cases know that Dr. Baden has been both an investigator and expert witness in homicide cases that include Nicole Brown Simpson, the alleged last victim of Albert DeSalvo, "Sunny" von Bulow, Ted Binion, and JonBenet Ramsey. He also served on the Forensic Pathology Panel of the U.S. Congress Select Committee on Assassinations, which investigated the cases of President John F. Kennedy and Martin Luther King, Jr.
The co-author of two books, Unnatural Death: Confessions of a Medical Examiner and Dead Reckoning: The New Science of Catching Killers, Dr. Baden also hosts HBO's Autopsy series. A resident of New York, he's a visiting professor at John Jay College of Criminal Justice, Albert Einstein School of Medicine, Albany Medical Center, and New York Law School, and also lectures extensively to law enforcement agencies."