Kristin Rossum

Kristin Rossum

by Chilling Crimes July 12, 2021

“I pulled back the covers and I saw that there were red rose petals everywhere, all over his chest. And he had a photograph of our wedding day up by his head near the pillow.’’

-Kristin Rossum

It was the 6th of November 2000. A Monday. Twenty five year old Kristin Rossum called 911 at 9.22pm from her home in San Diego, California, United States. She told the dispatcher that her husband, twenty six year old Gregory de Villers, wasn't breathing and that he had committed suicide. They advised her to administer CPR but it didn't help. When paramedics and police arrived, he was declared dead.

Kristin and Gregory had been married for just seventeen months.

Kristin told police that that evening, Gregory seemed a bit groggy but she thought it was just the effects of cold medication. Kristin told police that she had a bath and when she got out of the bath, she found Gregory lying on the bed and he wasn't breathing. The scene perplexed police. Gregory was found lying in his bedroom on the floor in the middle of rose petals. His wedding photo was near his pillow and crumpled up pages from Kristin's diary were found on the floor. Kristin told them that she moved him on to the floor to administer CPR. Police thought it was like a scene from the movie American Beauty. 

Kristin Rossum and Gregory de Villers

Kristin Rossum and Gregory de Villers

Initially, Kristin told the paramedics that Gregory had not taken any drugs but she later told them that he may have taken oxycodone. At the hospital, Kristin told a nurse that Gregory may have overdosed on oxycodone.

Police looked at the possibility that Gregory died as a result of an accidental overdose of cold medicines and oxycodone. They also discovered, through talking with Kristin, that he was upset as their marriage appeared to be over and that was why she told them that he committed suicide. That was a line of enquiry they also looked into. 

Kristin told police that the rose petals found around Gregory's body were from a bunch of roses he bought her for her birthday on the 25th of October. One rose survived and she believed he used the petals from that as a symbol that their marriage was over. 

Gregory's family told police the night his body was found that they did not believe he committed suicide. They weren't the only ones who suspected foul play. On the 8th of November, one of Kristin's coworkers, Russ Lowe, called the police. He informed them that Kristin was having an affair with her manager. That changed the course of the police investigation. 

Police looked into their marriage. Kristin and Gregory met in 1995 and married in 1999. When they met, Kristin was abusing methamphetamine but with the help of Gregory, she stopped and graduated summa cum laude with a degree in biochemistry. Kristin was hired by the San Diego County Office of the Medical Examiner (the OME), as a toxicologist, a toxicologist analyzes bodily fluids to determine whether drugs are present, in March 2000. Gregory was a biotech industry worker.

Gregory de Villers

Gregory de Villers

Shortly after Kristin began work at the OME, an Australian citizen called Michael Robertson was appointed to the position of Forensic Laboratory Manager. He replaced Russ Lowe. Russ, unlike Michael, had worked for a long time at the OME and had been serving as acting laboratory manager so when Michael got the permanent position instead of him, there was a bit of tension in the laboratory. 

The tension only got worse when employees found out that Kristin and Michael, who was also married, were having an affair. Some of the employees were worried that Kristin would get preferential treatment. A few months later, in October 2000, Kristin began using methamphetamine again.

Police discovered that Gregory confronted Kristin about her drug use and his suspicion that she was having an affair on the 2nd of November 2000, just four days before he was found dead. Gregory demanded that she resign from the OME. He told her that if she didn't resign, he would tell her employer about the drug use and the affair.   

An Autopsy was carried out and toxicology tests were conducted. When the medical examiner, Dr Blackbourne, received the results of the toxicology tests, he concluded that Gregory died of acute fentanyl intoxication.

Toxicology tests showed that Gregory's autopsy specimens contained extraordinarily high concentrations of fentanyl, as well as a smaller amount of clonazepam and a trace level of oxycodone. When police asked Kristin where he would have gotten fentanyl, she told them that she did not know. Police were aware that Kristin, through her work as a toxicologist, would have had access to fentanyl. Police believed that Kristin poisoned Gregory by giving him the fentanyl without his knowledge. They built a case based on the toxicological and medical evidence.

Kristin was charged with first degree murder. She pleaded not guilty. 

Kristin’s parents, Ralph Rossum and Claremont McKenna,  mortgaged their home to raise money for her  $1.25 million bail during the Trial and due to that, there was no money available to hire a private attorney. The Court ordered a public defender to represent Kristin. 

It was the Prosecution's case that Kristin killed Gregory because he threatened to tell her boss that she was using drugs and having an affair with Michael Robertson.

It was the Prosecution's case that Kristin poisoned Gregory using fentanyl. The Court heard that fentanyl is a powerful synthetic opiate and 80 times more powerful than morphine. They believed that she may have tried to kill him with clonazepam but when that didn't work, she gave him fentanyl. They also claimed that she then staged the bedroom to make it look like Gregory committed suicide by ripping pages from her diary and placing the petals and wedding photo around his body. 

The Court heard that Kristin graduated with a degree in biochemistry and used her knowledge of drugs and chemistry to kill Gregory. The Court heard that it was the Prosecution's case that Kristin hoped she could convince her colleagues at the medical examiner’s office that Gregory's death was a suicide. Normally, the cause of death in unusual cases is determined by the medical examiner's office, the very same office where she worked. But due to a conflict of interest, it was moved from there to another laboratory to carry out the toxicology tests. 

The Prosecution outlined Kristin's day that day, the 6th of November, for the Jury. Early that morning, she called Gregory's employer to let them know that he wouldn't be in and then she went to work. Her colleagues testified that an hour after she arrived at work, around 9am, she was seen crying in Michael's office. 

The manager of the apartment complex where Kristin and Gregory lived testified that she returned to her apartment at 12.10pm and he saw her run inside. She went to a local grocery store and purchased a few items at 12.41pm. 

During the hours before Gregory died, she made repeated calls to Michael. 

There were rose petals found around Gregory's body and Kristin told police that they were from the one rose that had survived from the bunch of roses Gregory bought her for her birthday. But the Court heard that police found a receipt showing that Kristin had purchased a single rose the same day that Gregory died. 

The Court heard how Gregory died and the high levels of fentanyl that were found in the samples tested.

Kristin Rossum and Gregory de Villers

Kristin Rossum and Gregory de Villers

Dr Brian Blackbourne, the San Diego County Medical Examiner, who performed Gregory’s autopsy, testified that Gregory had been dead for at least an hour before the paramedics arrived. He told the Court that he had developed early bronchopneumonia. That is a condition that results when secretions that are normally removed by the breathing process accumulate in the lungs because the person is either “unconscious or not breathing very deeply.”

Dr Blackbourne  also told the Court that Gregory had a substantial amount of urine in his bladder. This would have been very uncomfortable for him if he was conscious. That led Dr Blackbourne to conclude that Gregory had been not breathing properly for around six to twelve hours prior to his death.

Dr Blackbourne testified that the amount of clonazepam found in Gregory's blood was not at the level of an overdose and “not fatal.” 

The Court heard that the fact fentanyl was found and especially in such high levels was not usual and the OEM did not ordinarily test for it. If the OEM had carried out the tests as they normally would have, they would not have tested for fentanyl. But due to the conflict of interest, samples were sent to Pacific Toxicology and they tested for fentanyl. 

Dr Theodore Stanley testified on behalf of the Prosecution. Dr. Stanley testified that fentanyl is a potent and is a fast acting pain reliever. He told the Court that there is a serious side effect associated with it. It can cause a person to stop breathing.

Dr Stanley testified that the speed with which fentanyl takes effect depends on the manner in which it is administered:

"the peak effect occurs about sixteen hours after administration of a transdermal patch, twenty to thirty minutes after oral consumption, fifteen to twenty minutes after intramuscular injection, and five minutes after intravenous injection."

Dr Stanley told the Court that fentanyl is not normally administered orally because when taken this way, the liver destroys about 65 percent of it so only 35 percent enters the bloodstream.

When asked to explain how the fentanyl entered Gregory's body, neither Dr Blackbourne nor Dr Stanley could provide a definitive opinion. 

Dr Stanley testified that the differing concentration levels in Gregory's system, along with the evidence indicating that Gregory had been unconscious and breathing shallowly for hours before his death, suggested that fentanyl likely had been administered to Gregory on multiple occasions.

The Prosecution could not tell the Jury with any certainty how Kristin poisoned Gregory but there were indications that she may have applied patches containing fentanyl to his arm while he slept.

The Court heard that after Gregory died and after fentanyl was found to have been used, the OME audited its impounded drugs and drug standards. That audit revealed that fifteen fentanyl patches and ten milligrams of fentanyl standard were missing.

The audit also revealed that Kristin had logged in the fentanyl standard and had worked on each of the three cases in which the missing fentanyl patches had been impounded.

The OME also determined that quantities of methamphetamine, clonazepam, and oxycontin (a time-released form of oxycodone) were missing.

It was the Defense's case that Kristin was innocent. They conceded that fentanyl caused Gregory's death but it was the Defense's case that he committed suicide because he was despondent over his marital problems.

Kristin testified at the Trial. She told the Court that when she woke up the morning of the 6th of November, Gregory seemed out of it. She called his employer at 7.42am and left a message to let them know that he was ill and wouldn't be at work that day. She told the Court that she went to work but returned to the apartment to check on Gregory. She ate lunch with him after midday. 

Kristin testified that she asked Gregory why he had been so out of it that morning and he told her that he had taken some of her oxycodone and clonazepam. She said that he went back to bed after lunch and she went back to work. She left work at 2.30pm, went back to the apartment and then met Michael. She returned to the apartment at around 5pm and left again at 6.30pm to run some errands. According to Kristin, she got back at 8pm and had a bath. 

Kristin testified that when she got into the bath, she believed that Gregory was asleep and only noticed he wasn't breathing when she got out of the bath. That was when she called 911. 

The Prosecutor cross examined Kristin. He called her explanation “bizarre”. She admitted she had lied about things in the past and lied about her drug use. He told the Court that fentanyl was “the perfect poison” because it is difficult to detect, something she was well aware of due to her job. 

The Defense argued that even though Dr Blackbourne testified that the amount of clonazepam found in Gregory's blood was not at the level of an overdose and “not fatal,”  if oxycodone which is an opiate, and clonazepam which is a benzodiazepine are taken together, they can have a synergistic effect on each other making them more powerful. But that did not explain how the fentanyl was taken and why there were such high levels of it found. 

The Jury deliberated for eight hours. They found Kristin guilty of first degree murder and of murder by special circumstances due to the use of the poison. She was sentenced to life in prison without the possibility of parole.

Kristin appealed her conviction. The Appeals Court heard that mistakes were made by her own Defense team. Her attorneys conceded that fentanyl was the cause of death but they failed to have the autopsy samples tested for fentanyl metabolites.

That test would have allowed them to establish if Gregory had ingested fentanyl or whether fentanyl found in the samples was a product of laboratory contamination subsequent to his death. If the fentanyl was found in the samples only and had never been in Gregory's body, then the prosecution's theory that fentanyl was the cause of death would have been proven wrong.

But how would the fentanyl be in the samples only and why would there have been any possibility of laboratory contamination if the OEM sent the samples to a different laboratory to test them?

The Appeals Court heard there was a break in the chain of evidence in relation to the samples. 

The samples were placed in a cardboard box, with each container marked as a sample taken from Gregory's body, and the containers were not sealed. They were supposed to be transported to the sheriff's office for transfer to the outside laboratory immediately but the person who was to receive the samples was not available so the box containing the samples was held in the OME. The box remained there for some thirty six hours until it was taken to the sheriff's crime lab.

The argument before the Appeals Court was that anyone with a key to the OEM building had access to the samples. The fentanyl could have been added to the samples after Gregory's death. Kristin believed there was motive to contaminate the samples and frame her for murder because of the various personal relationships and tension among the OME's employees. In fact, Kristin further outlined in the argument before the Appeals Court that on the 8th of November 2000, Michael commented to one of the toxicologists at the OME that he had looked at a sample of Gregory's stomach contents.

Michael Robertson

Michael Robertson

A three judge panel of the 9th U.S. Circuit Court of Appeals concluded that Kristin’s trial lawyers erred by not challenging the Prosecution’s contention that her husband died from an overdose of fentanyl. They stated that her legal team should have tested the autopsy samples for metabolites of fentanyl and not simply conceded that that was how he died. 

That said, they did not reverse the conviction but sent the case back to federal court so that a hearing could take place to determine if that error by the Defense would have changed the outcome of the Trial. 

However, since that decision was made, the US Supreme Court, in dealing with a different case, a case which involved a man convicted of murder seeking to have his conviction overturned because of mistakes the Defense made in his Trial, determined that federal courts must defer to a state court’s decision when considering such claims.

Based on that ruling, the Appeals court panel voted not to order the hearing in Kristin's case. Her Appeal was denied and she remains incarcerated. 

Michael Robertson was referred to as a co-conspirator at Kristin's Trial. He returned to Australia and set up a forensics consultancy services firm. 

Gregory's family sued the county, alleging negligence for allowing Kristin to steal a fatal dose of drugs from the medical examiner’s office without being caught. A US Court awarded them a $147 million civil payout in 2006.


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