DNA testing is virtually infallible when used to determine a person's identity, but how reliable are the people responsible for conducting the investigations?

That question is at the heart of the case of two college students, Laura VanRyn and Whitney Cerak, who were involved in an April 26 car crash in Upland, Ind. One of the women, thought to be Cerak, was pronounced dead on the scene by local coroner Ron Mowery. He said he relied on the dead woman's friends and physical evidence found at the accident scene, including a photo ID, to make his identification. Four days later, the woman thought to be Cerak was buried.

Meanwhile, the other woman, thought to be VanRyn, was taken to an area hospital. The VanRyn family stayed by the woman's bedside for five weeks, thinking it was their daughter. All the while, doctors, too, believed they were treating Laura VanRyn. It wasn't until the woman was able to communicate that her name was Whitney that the VanRyn family knew something was terribly wrong. Doctors later confirmed through dental records that the woman was not VanRyn, but instead was Cerak.

Experts believe the mix-up of the two Taylor University students was due to a combination of questionable training and inadequate scientific procedures and equipment.

"I would imagine that over 90 percent of all death investigators are not certified," said Brian Gestring, an associate professor of chemistry and physical sciences at Pace University in New York.

"There is a fundamental difference between medical examiner and coroner systems that really should be the heart of this issue," explained Gestring, a certified forensic scientist who says he has worked as a death investigator, in a DNA lab, and as part of a crime scene reconstruction unit and the World Trade Center Identification Unit. "In short, there is no mandated level of training for coroners. I'm not saying that this mistake could not have happened at a M.E., but the lack of training that most coroners posses is a real issue."

He added that protocols usually are set by the individual agency.

"In a case like this, I would accept nothing less than a visual ID from a family member that identified a unique tattoo or scar, medical or dental records [showing previous fractures of dental work], fingerprints or DNA," Gestring said.

Not Every Coroner is a Trained CSI

Medical examiners are physicians, pathologists or forensic pathologists with jurisdiction over a county, district or state. They have degrees in areas such as DNA analysis and forensics, and they know how to run DNA tests to make mathematically certain they are identifying the right person.

A coroner, on the other hand, is an elected or appointed official who usually serves just one county and often is not required to have formal medical training or a minimum level of education in death investigating. In fact, many coroners are known to take the position as a side job.

Lisa Barker, executive director of the Indiana Coroner's Training Board, said that 53 out of Indiana's 92 county coroners are certified medicolegal death investigators; only three coroners are full-time, elected positions. The coroner's board offers a 40-hour death investigators course, but elected coroners are not required to attend; coroners follow local protocols based on national guidelines, such as those released in 1999 by the Justice Department and approved by the National Medicolegal Review Panel.

Many part-time coroners have full-time jobs that range from doctors, funeral directors and paramedics to office managers and truck drivers.

"Currently, guidelines are being reviewed to see what or if any changes are needed," Barker said when asked if the VanRyn/Cerak case caused the state to rethink its system.

In contrast, Texas has a stringent protocol death investigators must follow when identifying bodies.

"First, we would look at fingerprints, which many states have through motor vehicle records or if the person had a criminal background," said Joseph Warren, who specializes in forensics at the University of North Texas Health Science Center at Fort Worth. "Then we would look at dental records, which are very easy to do. Then we could go to medical testing by using medical records or comparing post-mortem and pre-mortem X-rays. Then there is DNA testing."

Even without having a death investigator certification, there are many technologies available to help correctly identify bodies, even for smaller municipalities, experts said. DNA tests are inexpensive, but many towns do not have the required testing equipment. In that case, many coroners and medical examiners will use state police facilities to conduct tests, Warren said.

In the case of Cerak and VanRyn, Warren said a simple nuclear DNA test could have been performed to prevent the mix-ups. Nuclear DNA is the DNA that makes up our chromosomes, found in the nucleus of cells, and consists of inherited traits passed down from biological parents.

"In this case, they could have gotten DNA from parents and from the deceased and then run DNA testing on blood, cheek cells or any other tissues, and then done a reverse paternity testing to get a DNA profile," Warren said. "After this, it would be very easy to see who the child would be, and then simple math would give 100 percent certainty that this is, or is not, the child."

He added that it's also possible to collect DNA from a toothbrush or razor used by the potentially deceased and compare the samples to DNA collected directly from the victim. This method was used to identify victims of the Sept. 11, 2001, attacks on the World Trade Center.

Even if the bodies were decomposed, Warren explained that there is more in-depth mitochondrial DNA testing that links directly to the biological mother's DNA.

Other experts say a misidentification can happen anywhere, to anyone, and it's not simply the system to blame.

The National Association of Medical Examiners (NAME) is an organization made up of about 900 members who range from medical examiners and coroners to administrators and investigators; about 400 of the members are certified forensic pathologists.

In 2005, the group adopted standards in death investigation that suggest the medical examiner, or the one who is certified, should be the only one in charge at the scene of a death investigation.

John Hunsaker, president of NAME and a medical examiner in Kentucky, acknowledged that although 400 is a "relatively low number considering needs and meeting professional standards," the group's members are supportive of setting up forensic pathologist standards.

"It's not so much that the systems are not in place and have stood the test of time, it is sometimes the failure to follow what the system requires," Hunsaker said. "I don't know every medicolegal death investigation office. I would say that it is rare that there are misidentifications, but it can happen in any office."