Saturday, June 30, 2012

Suicide or Homicide? Evidence that CSIs Consider

Charlotte Hinger here, welcoming our guest blogger Tom Adair. From investigating the shootings at Columbine High School to locating gravesites in the remote back country of the Rockies, Tom Adair has lived a life most crime authors only write about. An internationally recognized forensic scientist, he has a Bachelor’s degree in Anthropology and a Master’s degree in Entomology. He has served as the president of the Association for Crime Scene Reconstruction, Rocky Mountain Association of Bloodstain Pattern Analysts, and the Rocky Mountain Division of the International Association for Identification. While in law enforcement he was board certified as a senior crime scene analyst, was one of only 40 board-certified bloodstain pattern analysts and one of 80 board-certified footwear examiners worldwide. In addition to writing over 60 scientific papers, he has served as the editor of an international peer-reviewed science journal. Over his 15 year career he has been interviewed by and consulted for television, text books, novels, magazines, and newspaper articles as well as documentaries on the Discovery Channel and National Geographic. He continues to teach and conduct research in the forensic sciences. When he’s not writing he enjoys hunting, hiking, fishing, and camping in Colorado’s back country with his wife and chocolate lab.

Suicide or Homicide?

Any death investigation is challenging. Aside from the complexities of the crime scene there are the living "victims" (like family members of the deceased) who can add a tremendous amount of stress to the investigation. That is never more true than when the family or the public believes the manner of death to be different than the evidence suggests. There is no way to predict how others will judge a death and I suppose that adds to the stress too. I've investigated deaths where the manner (suicide/homicide) was obvious but others interpreted the evidence differently. Suicides are extremely emotional. Loved ones can experience a whole range of emotions like sorrow, anger, even guilt. The most powerful can be denial. No one wants to think that a family member would decide to end their life. If the victim is a public figure or celebrity then the ante goes up. The public's perception of a celebrity may be the polar opposite of reality. In fact, some people falsely believe that a rich and successful celebrity couldn't possibly contemplate ending their "charmed life". When that happens the fans may believe the death was a homicide. In homicide cases, the only person who typically wants to suggest "suicide" is the killer. In fact, if a family member or friend continues to "push" the idea of suicide (when the evidence of homicide is clear) then they quickly become a suspect.

Either way, it makes no difference to the CSI. We want to find the truth, whatever that may be. I should mention that none of these conditions may tip the scales one way or another by themselves. In fact, there are some deaths in which the manner can not be determined (hence the term undetermined). It isn't necessarily the lack of data. It may simply be that a key piece of evidence can be viewed both ways. A gunshot wound t the head could be homicide or suicide depending on certain indicators. Just because the gun may be next to the body doesn't necessarily prove suicide. Additionally, I have seen some truly bizarre death scenes in which the victim chose an unusual or extremely painful way to end their life. These are the exceptions to the rule however. So what kinds of evidence do CSIs look for when evaluating a death?


The central aspect of suicide is the absence of actions by another person. In simple terms that means that the victim must be physically and mentally capable of completing all of the actions comprising the act. In gunshot suicides the victim must obviously have access and familiarity with the firearm and ammunition. But that isn't enough. If they used a rifle or shotgun then their arm has to be able to reach the trigger to function the weapon. If the barrel length is 38" but their arm length is only 30" then there is a problem. Likewise, the distance between the weapon muzzle and victim must be believable. If the gun was fired from over three feet away then it's hard to argue suicide. Suicides are all about the victim. As such, understanding the victim's life history becomes very important. There are a few things that an investigator has to consider regarding the victim.
  • A history of suicide attempts, depression, mental illness, etc. 
  • Recent traumatic events such as loss of job, financial troubles, loss of a loved one, troubled relationships, etc.
In addition to that there is the scene to consider. Because suicide is a personally motivated act the scene should be devoid of any other motive for the death. That means there shouldn't be anything of value missing (robbery). There shouldn't be signs of a struggle (defensive wounds). Now sometimes a suicidal person may break valuables or overturn furniture as an act of frustration or depression but there should be no evidence of another person present. There should be no evidence of forced entry to the scene. Any injuries should be consistent with the method of taking their life. It isn't enough that investigators find an empty pill bottle next to a victim. The autopsy must reveal that a fatal level of said drug was present in their system before proving suicide. Everything on scene and at autopsy must confirm that the victim could and did take their own life without evidence of others involvement.


Unlike suicide, homicide requires a killer and an unwilling victim. Homicide is motivated by any number of things like jealousy, revenge, profit, contempt, not to mention plain old homicidal mania. There may be evidence of forced entry or a violent struggle. If the killing is incidental to the main motivation for the crime (such as home invasion robbery) then there may be evidence of ransacking or items of value that have been stolen. Homicide may be for the purpose of eliminating a witness so we will look for evidence of things like rape or whether the victim is scheduled to testify in a criminal trial or witnessed a criminal act. Most criminals also take the murder weapon with them when they leave (although not always). So the absence of a weapon may support a finding of homicide along with other conditions.

Because homicides require a killer, there should be clear evidence left from that killer such as blood, semen, shoe impressions, fingerprints, etc. A victim may have the killer's skin under their fingernails. The killer's boot prints may be on the floor next to the body. In some cases the killer may try to cover up the crime by staging or even setting fire to the crime scene. Obviously, we talk to friends, family, co-workers and others to see if the victim had any enemies. The motives for some killings are years in the making. In these cases, motivations for rivalries, jealously, or revenge may be well known and documented. You still have to find the evidence though. Ultimately, the evidence directs investigators to the proper manner of death. That is, if they find it. Differentiating a suicide from a homicide might hinge on one or two pieces of evidence. If those items are not present or recognized then investigators may get it wrong. This is good news for authors. By writing a scene in such a way that these clues are missed we can change the direction of the story. Then, when the item is found again the story makes a U-turn and the readers straps in for a roller coaster ride. Consider ways you can introduce this challenge. Maybe a victim takes their life with an expensive gun and the reporting party steals it. Whatever you choose don't be afraid to get a little creative. I assure you the reader will appreciate the effort.

Tom also blogs at Forensics4fiction and the Crime Fiction Collective. Check out his website at


Charlotte Hinger said...

Tom, your talk at Rocky Mountain Mystery Writers was wonderful. Just wish we recorded all of these and could pass them along.

Frankie Y. Bailey said...

This is a post that my criminal justice students would enjoy. So did I.

entrance doors said...

I think it was a homicide. That's just my opinion. Let's just let the professionals do their works.