Students Learn the Laws of Science Through a Forensic Investigation

Students Learn the Laws of Science Through a Forensic Investigation

By Carolyn Arnold

It was late afternoon at Fairfield’s Bannow Science Center. Dr. Susan Rakowitz, professor of psychology, was returning to her office when she sensed a disturbance. Someone, dressed in black, ran out of her office. A shot rang out.

Looking warily into the office, Dr. Rakowitz was horrified to see it in disarray. Someone had broken into her file cabinet. Blood covered the disheveled files. Someone had clearly been looking for something … but what?

Okay, so this case isn’t quite ready for 48 Hours. In fact, Dr. Amanda Harper-Leatherman, assistant professor of chemistry, had orchestrated the crime for the benefit of the students in her honors course, “Introduction to Forensic Science.”

This course was developed as a core science course by Dr. Harper-Leatherman and Dr. John Miecznikowski, assistant professor of chemistry, and was first taught by Dr. Miecznikowski in Spring 2009. It teaches students about the scientific techniques used for the analysis of physical evidence found at crime scenes.

During the term, students are charged with solving a mystery by recovering evidence from a crime that has been staged for the purposes of the investigation, leaving behind

traces of DNA, fingerprints, hair samples, and other evidence. Students then use the tools of forensic science to identify the guilty parties.

Students Greg Burke ’12, Jon Hurdelbrink ’10, Angelica Mack ’10, Mary McGrath ’10, and Adrianna Sutfin ’11 were assigned to Dr. Rakowitz’s case and would spend the fall semester solving the mystery.

The students signed up for the course for a number of reasons. Hurdelbrink, an economics major said, “It was a great opportunity. Everyone in the class has a diverse academic background and were all on the same level with our science skills.” Burke, an accounting and economics major, simply said, “There’s no other time I would be able to take a forensics course!”

Back at the scene of the crime, Dr. Rakowitz was reeling. “I was shocked and dismayed to find my office open and my papers rifled through. I could see immediately that an envelope marked ‘confidential’ was empty.” The file had contained papers related to a fictional, top-secret faculty committee, Dr. Rakowitz said. “So I knew the theft was linked to that committee.”

Once the students arrived, they dusted for fingerprints, and recovered hair and blood samples. They also found a spent bullet.

The team narrowed down the suspects to the members of the fictional committee, which included Drs. Brian Walker (biology), Shawn Rafalski (mathematics), Laura McSweeney (mathematics), and Robbin Crabtree, dean of the College of Arts and Sciences.

When Dr. Walker was interviewed he stated, “My history of pure innocence in all things really speaks for itself. That, and I can’t lie to save my life.” A weak alibi at best.

Still, the students analyzed the footprints found in the office and concluded that they most likely belonged to a female. Sutfin, a nursing student who took the course due to a love of Nancy Drew novels said, “The shoeprints were informative. We surmised that it was either a woman, or a man wearing small women’s shoes. That narrowed our suspect list down substantially.”

What of Dean Crabtree? She maintained that she was in her office prior to the crime and readying herself to go to the train station. Staff members vouched for her. But did she go to the train station alone? The students decided to wait for the evidence to tell them more.

Dr. Rafalski recalled that he had been teaching class when the crime took place. However, he told the investigators that he had met with Dr. McSweeney shortly after the crime had occurred and that Dr. McSweeney had been acting strangely.

“I can’t be sure about this,” he said tentatively, “but I think she might have been out of breath. She could have committed the crime and then run down the stairs to meet me.”

Forensic evidence would prove that at least one of the suspects wasn’t telling the truth.

Microscopic analysis of the hair found at the scene compared to that of the suspects revealed little. The hair samples were imbricate (they resemble flattened scales) and had amorphous continuous medulla, which is consistent with human hair. But comparisons at first proved inconclusive.

“Basically, we were able to find out that all of our suspects were human,” joked Hurdelbrink. Yet, based on the color, thickness, and degree of curl of the hairs found at the scene, the students concluded that they most closely matched those of Dean Crabtree. The plot thickened.

Next, the students did an analysis of the bullet found at the scene. Dr. Harper-Leatherman gave the students bullets that were test-fired by the police from guns, allegedly owned by Drs. Walker and McSweeney (in actuality they were from a firing range).

Handguns have spiral lands and grooves in the barrel that create a spin on the bullet and improve accuracy, and leave distinctive rifling marks on a bullet. Based on the number and thickness of the lands and grooves the students concluded that the bullet matched Dr. McSweeney’s gun.

After dusting for fingerprints, the students compared them to their suspects’ prints and were fairly certain that they had a match. Still, they wanted to make sure all of the evidence was weighed evenly before they made accusations.

They did DNA analysis on the blood sample by using PCR (polymerase chain reaction) technology and gel electrophoresis. PCR is a reaction that targets a specifically chosen segment of DNA that is unique to an individual, and makes many copies of this segment. PCR makes it possible for forensic investigators to take even the smallest sample of saliva, blood, or skin found at a crime scene and to amplify the DNA information in the sample that is unique to one individual, so it can be compared to DNA samples from a victim or suspect. Gel electrophoresis uses an electric field and a porous gel to separate the unique DNA segments amplified by PCR found at the crime scene, to be compared to that of the suspect. Each specific segment of DNA found in one sample shows up as a band of different lengths along the gel. The investigator can then compare the pattern of bands produced by each sample to try and find a match, and thereby place the suspect at the crime scene.

Mack, a politics major, said this was her favorite part of the lab work. “DNA analysis was cool because it gave us definitive information, whereas the rest of our evidence was not entirely conclusive.”

The data was in. The DNA of the blood in the office and the fingerprints matched … Dean Robbin Crabtree! When confronted by the students, Dr. Crabtree said, “Look, these committees get the best of all of us sometimes. So, if I did do it, though I’m not saying that I did, then it was clearly a crime of passion.”

“All of the evidence places the dean at the scene,” said Mack.

But what about the gun? Dr. Crabtree didn’t have one. The gun was linked to Dr. McSweeney. “I am stumped as to why the bullet is linked to me. I think Dean Crabtree planted it in order to make it seem like I was guilty,” Dr. McSweeney claimed.

Trying in the end to save face, Dr. Crabtree said, “The hairs could have been planted. I could have been in Susan’s office a dozen times. As for the file with my blood on it, I could have gotten a paper cut when passing that file to Susan in a meeting. Anyway, the motive is flimsy. Who would believe that a dean would try to kill a faculty member?” she added.

Sutfin concluded that the mock crime had proved to be an excellent teaching tool, “We had to rely on what we knew and what we had learned to examine the scene,” she said. “We wanted to solve the crime. Also, it was an awesome way to learn forensics!”

In and beyond the laboratory

Dr. Harper-Leatherman, the mastermind behind the crimes, enjoyed teaching the forensic course because it was a chance to help students move beyond tentativeness in the lab room. “To some students, just being in the lab is potentially daunting. This course was fun and exciting to them.” By the end of the course, students had gained confidence by using lab skills to solve problems.

The course also gave students ample opportunities to discuss scientific concepts as they relate to current events and other academic disciplines. “They learned about the nitty-gritty details in the lab, and then they saw how they apply it to the real world,” said Dr. Harper-Leatherman. This included discussing the pros and cons of legalizing marijuana, the ethics of crime scene processing, and the pros and cons of a national DNA database.

In addition to labs, lectures, and lively discussions, several guest speakers were brought in to share their experiences as they relate to forensic science. Gus Karazulas, DDS, spoke about his work as a forensics dentist for the Connecticut State Police. Karazulas, a Fairfield alumus of ’55, worked on many violent crimes such as the Elizabeth Smart kidnapping. Noting that humans are fallible, he stressed the importance of the advancements science had made in helping solve crimes.

Another guest speaker, the Honorable Mark T. Gould, a judge at the Judicial District Courthouse in Bridgeport, Conn., talked with students about the Daubert standards which are the rules of evidence regarding the admissibility of expert witnesses’ testimony. Forensic scientists take this role when they testify in the court room.