Rebecca Marion

Ads Manager

Douglas E. Rohde, supervisor of chemistry and toxicology at Lake County Crime Laboratory, educated participants with a detailed account of how chemistry led to a murder conviction during a presentation at Lorain County Community College in the iLoft building on April 1st.

Using chemistry as a binding agent, Rohde made use of TV clips and PowerPoint slides to soften scientific jargon and round out his presentation on Rosemarie Essa’s murder.

On Feb. 24, 2005, Dr. Yazeed Essa, an emergency room employee, handed his 38-year-old wife and mother of two children, Rosemarie Essa, two calcium supplements before she left the house to attend a movie with her sister.  On the way to the theater Essa began to feel sick and at 2:02 p.m. her SUV sideswiped another vehicle. While the driver of the other car was uninjured, Essa was not speaking, although her eyes open and she was vomiting.  Minutes later, the EMTs and the Highland Heights Police Department arrived to assess the scene. Essa was transported to Hillcrest Hospital emergency room, where she was pronounced dead after 30-40 minutes of resuscitation by the ER staff. Her autopsy, performed the next day, concluded that the car accident was not the cause of her death.

The coroner’s office was at a loss to determine what caused the rapid death of a healthy 38-year-old woman with no medical conditions. The only option left was to wait on the toxicology report, which would take weeks to yield any answers.

While they waited for the toxicology report the Highland Heights Police Department received a call from Essa friend, Eva McGregor, who recalled speaking with Essa just before her car accident. McGregor told police that Essa had mentioned feeling ill on her way to the movie theater, and said she would call her husband to see if the calcium supplements he gave might be making her sick. This prompted detective Gary McKee to interview Dr. Essa, who admitted to giving his wife coral calcium supplements and prenatal vitamins. McKee was given permission by Essa to take all the medications from the household as evidence. That same day, Essa called his in-laws and told them that he needed them to watch the kids because he was going out of state to help a friend in North Carolina who had been in an accident. Shortly after that, Rosemarie Essa’s family reported their son-in-law missing after discovering an empty envelope from the passport agency.

Several days later, Detective McKee handed Rohde a box of vitamins and supplements taken from the Essa home. The coral calcium supplements peaked Rohde’s interest. Not only were they the last medication given to Rosemarie, but it was odd that they were in capsule-form as most of the calcium available was in a pill. “It wasn’t the first thing you would grab if you wanted calcium. It was a little bit of an effort to grab this type,” noted Rohde. This was the only medication in the box in capsule-form that you could untwist and empty the contents. Rohde’s first clue that something was amiss came by the appearance of the pills. “You could see the differences. There was a pile that looked powdery and then a few that had a crystal appearance,” Rohde said. Upon further inspection, he noticed that the capsules containing a powder substance had bits of rose-colored coral in them, while the capsules containing chunky crystals did not. Fresh off of a previous case involving cyanide, Rohde suspected that he knew what the crystal substance was. The first idea that occurred to him was to run the sample on the gas chromatography mass spectrometry to test for cyanide immediately.

The results surprised Rohde. He expected to find lubricants on the capsule because of its use in the pill press, but not on the crystals. That was his second hint that the pills may have been tampered with. Still concerned about the presence of cyanide, he ran the sample against a standard on the spectrometer. Minutes later, the test results showed that the crystals were most likely cyanide.

“This is by no means definitive. It was barely presumptive, but at least perhaps, it ruled things in and out,” Rohde said. To ultimately confirm the presence of cyanide, he needed a confirmatory test. So he used x-ray fluorescents in the trace department to perform an elemental analysis to determine if the powder was calcium and if the crystals were potassium. The test results confirmed that the crystals contained potassium. That night Rohde went home before telling detective McKee of his findings.  “I really wanted to mull it over because I knew once the ball went rolling that Dr. Essa was going to be charged with murder,” said Rohde. The next morning, Rhode went over the data again and called Detective McKee, informing him that what had killed Essa was cyanide.

Still, Rohde wanted more evidence and so did the Highland Heights Police Department.  On April 22, 2005 Rohde used a C-13 NMR Spectroscopy to ultimately determine the presence and purity of the cyanide in the capsules. The results showed that nine of the capsules contained 100 percent pure cyanide. Blood tests screening for cyanide revealed that Essa had three times the lethal dose of cyanide in her system.  Adding the evidence together, the Cuyahoga County Coroner’s Office determined that beyond a reasonable doubt Essa’s cause of death was acute cyanide intoxication. Rohde reached out to the U.S. Food and Drug Administration Forensic Chemistry Center in Cincinnati to determine where the cyanide was produced, but they were unable to determine that information. Detective McKee soon discovered that Dr. Essa had access to cyanide through the jewelry shop he owned with his brother. The evidence strongly pointed to Essa as the guilty party.

In October 2006, a year a half after his wife’s murder, Dr. Essa was arrested in Cyprus and extradited back to the United State. Four years later, on March 9, 2010, Dr. Essa was tried and found guilty of murdering his wife and sentenced to life in prison with no chance of parole for 20 years.

The successful conclusion of Rosemarie Essa’s murder investigation, along with the eventual sentencing of her husband, Dr. Essa, was made possible through forensics. Rhode’s work is significant in bring criminals to justice in Lake County. This case is a great example of how science and chemistry can lead to a murder conviction.