– Transcript of Video –
Today we’re going to talk about bruising and the dating of bruises. I get calls on this on a regular basis regarding cases in which the victim has bruises. Whether it’s a child abuse case, a domestic violence case, or assault case, oftentimes the bruising is used as evidence to show that the assault occurred. The difficulty is that there are still many experts out there that think that bruising can be dated by color. Bruise dating for court cases can be tricky… Health care providers will document phrases such as “bruises of various colors and stages of healing,” or something similar that alludes to the fact that the bruises occurred at different times. The police officers will also document in their police reports that the bruise looks old, or it looks new, or it looks fresh. Anything along those lines of bruise dating.
As a general rule, you can’t date bruises and that’s mostly what I’m going to cover here… bruise dating. But I want to also define what a bruise is for you. You can also read about the characteristics of bruises for more info. In the medical field there are two words that are used for bruising; one is a contusion, which is from blunt force trauma. The impact of a hard object causes the capillaries under the skin to burst and the blood seeps out into the extracellular space, causing discoloration. The second term is ecchymosis, which is bleeding in the area where you see a visible discoloration; but in the case of an ecchymosis, the trauma is not necessarily directly over the area of injury. It may not necessarily be blunt force trauma either. An example of an ecchymosis is when you have a surgery done. You may see discoloration from the trauma of the surgeon cutting through the tissues and cutting open the blood vessels. In this example, it is a sharp object that causes the blood seep out into the extracellular space. So in an ecchymosis the blood may be coming from remote area and seeping through the path of least resistance or to gravity. In either contusion or ecchymosis, the discoloration on the skin will appear to be a bruise. So that is the major difference between an ecchymosis and a contusion: A confusion is from blunt force trauma and ecchymosis can be from blunt or sharp trauma. I will note that in medical records, I often see the term ecchymosis and contusion interchangeably used and that is due to the term ecchymosis being more of a forensic term and used to identify mechanism. The key point is don’t necessarily assume that just because it says contusion that it’s from blunt force trauma.
An assessment of the injury and the cause of the injury would be necessary to determine mechanism. The characteristics of a contusion are going to be related to the force of the trauma, where on the body it is located, underlying medical conditions such as tendency to bleed, and the depth of the injury. One of the common questions I get is whether there is a certain amount of force that caused the bruise; whether it indicates a great amount of force or whether it could be caused from minor trauma. There isn’t really an easy answer to that, but you can define it in relative terms. For example, let’s take a bruise on the abdomen where you don’t have a bony surface underneath the skin. It is going to take much more force to cause a bruise than say a bruise on your arm where you have a bone that’s lying directly underneath the skin. What causes a contusion is impact that causes blood vessels to burst, think of those blood vessels is little tiny balloons and you’re essentially squeezing them until they pop. It’s much easier to do that when you have a hard surface underneath the object that’s impacting it. I mentioned on the abdomen where you have a soft tissues and no underlying bone so it takes a lot more force to cause those blood vessels to burst.
As I mentioned before you cannot date bruises, but there are still many experts out there that will testify and say that bruises can be dated by color. They may say that a brown bruise is an old bruise, or a red bruise is a fresh bruise. People traditionally thought that red, blue and purple are considered to be young bruises or less than 48 hours old, that bruises that are brown, yellow, and green are at least a week old, and that if you see a mixture of colors they are between 2 and 7 days old. In truth, the science shows that color cannot indicate bruise dating. This is partly because what I consider to be blue, you might call green. We are often dealing only with photographs, and cameras and lighting may change the appearance and coloration of the bruise. The best practice is for health care providers and police officers to not document that a bruise is of varying stages of healing based off the color. Another best practice is to avoid testifying about specific photographs. For example saying “this bruise in this photograph is yellow or green and therefore must be at least 18 or 24 hours old” is problematic. However, in a hypothetical I can testify about the studies I talked about here, and say that yellow and green are associated with healing bruises and are representative of 18-24 hours or more. But if we have bruises that are up on the screen for the judge and the jury to see, I won’t try and date those specific bruises. Ongoing bruise dating research continues.
Another point to make is that bruises can be patterned where the characteristics of the bruise will match the approximate size and shape of the object that caused them. But we need to be cautious; for example, some experts will call a bruise a thumbprint bruise, when it is just an oval bruise. There are many many many bruises are circular or oval in nature, and just because it happens to be a similar size to a thumb does not necessarily mean that it is from a thumb. But let’s take a different example where we have a thumbprint sized bruise on the bicep and three or four matching bruises on the back of the arm: That matches the general shape and size of a hand. Because you’re taking into account more than one bruise, then we can say it is more consistent with a grabbing mechanism and could be considered a pattern injury. So, much like bruise dating, one bruise by itself is not necessarily going to be identified as a patterned bruise.