Talk:Bloodstain pattern analysis

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This article was the subject of a Wiki Education Foundation-supported course assignment, between 2 February 2021 and 17 March 2021. Further details are available on the course page. Student editor(s): GZhen. Peer reviewers: Jencastiel.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 15:59, 16 January 2022 (UTC)

Article ownership

Wikipedia:Ownership of articles I have left the following link for 66.141.34.101.

Untitled

This article, particularly the intro, reads more like a sales pamphlet about the topic than a serious encyclopedia article. It's pretty poor but I'm not the person to fix it. Anyway, just in case anyone who knows about the subject sees this, can someone explain to me how the whole point/area of convergance analysis is accurate if you take into account that any blood which is flying in an area with gravity will follow a parabolic arc? It seems to me that using straight line analysis (i believe investigators simply use string) will always overstate the actual height of impact which, incidentally, will often be advantageous to the prosecution's story if there's a factual dispute (eg was it a fall or a beating). Just wondering Psychobabble 23:56, 7 February 2006 (UTC)

==Psychobabble doesn't seem to understand the topic, and his comments are not reflective of the article itself, which is fairly high-quality and explains the topic in great detail. The tone needs work, however, and I have included a note to that effect. If Psychobabble wants to understand how investigators deal with the problem of parabolic trajectories, he should look up ballistics, as it deals with the same field and the same issues. Don't insult what is an otherwise a good article by trying to raise doubts where there are none.

I think the tone issue you identified was what I was getting at, 'tone' was my only criticism of the article. I wasn't criticising the content of the article in the other part of my statement, I was seeking an understanding because that was an issue raised in a crim law documentary I saw. You're right, I don't understand the topic which is why I asked the question and it was a question I saw raised elsewhere in the context of an investigation where trajectories were measured using straight line string. Feel free to enlighten me as to how this issue is dealt with in real life :) This article didn't clear it up for me which is why I asked originally. Psychobabble 04:06, 25 September 2006 (UTC)

Psychobabble, you are correct about bloodstain analysts using straight lines to approximate the path of the bloodstain trajectories. This is called the tangential method. An analyst tries to use fast upward moving stains whose flight path has had little or no effect due to gravity. The resulting area of convergence will always have a height greater than or equal to the event. There are computer programs like HemoSpat that do the calculations through digital imagery and on-scene measurements so the analsyt doesn't have to use real strings. As for the tone of the article, I tried to cover what I could at the time and I'm sorry for not getting back to tidy things up. I will look at making it more encyclopedia-like. Kevin Maloney 14:12, 29 September 2006 (UTC)

Thankyou. Psychobabble 21:49, 29 September 2006 (UTC)

MVIS and HVIS?

Whats inbetween the two? It goes from 7.5 meters a sec, to 30+ meters a sec. Whats going on between the 50 feet that are left out?

There are different ways of categorizing bloodstains. The method presented here is what is currently accepted by the IABPA. These definitions were created years ago and were based on studies done by some of the pioneers in bloodstain analysis. The MVIS categroy is meant to cover most blunt force attacks and show the restriction of how fast you, as the assaulter, can punch, kick, swing a hammer etc. The HVIS category is more of a mechanical based attack such as chainsaws, machinery, handguns, etc. However that being said, categorizing impact stains as LVIS, MVIS, and HVIS is only a guide. There are always exceptions like sneezing blood which can produce HVIS-like staining. Hope this helps. Kevin Maloney 14:27, 29 September 2006 (UTC)

I have a minor objection to the following statement: "Contrary to some points of view, bloodstain pattern analysis is not junk-science and requires education and training." Although I agree that BPA is not junk science, the statement is clearly not NPOV. If BPA has critics, (however few) their POV should not be marginalized by stating factually that they are incorrect. It is not appropriate to state factually that critics of BPA are incorrect. A similar statement on a more controversial topic would not be permitted. I believe that this statement should be removed, allowing the reader to make his or her own decision about whether or not it is junk science. If it is necessary to address criticisms levelled at BPA this should be done in a "criticism" or "critiques" section as is done on the rest of Wikipedia, rather than marginalizing a minority perspective by stating that the critics are incorrect.

I'm not sure how long the above statement has been here but the term "Junk Science" has been used in court to describe BPA. Judges have stated in their decisions that BPA is "not junk science" and required training. FYI. Kevin Maloney (talk) 02:18, 31 October 2008 (UTC)

controversy

First of all, well done! Whoever put this article did a great job! Good pictures, organization, writing. Very impressed.

I do think we should add some information on the controversies surrounding BPA, basically that you don't really know what "experts" are "experts". I know I've seen several cases lately where both sides have well known and respected analysts. How do you know who's right? I just came from researching the David Camm trial where the reliability of blood spatter really came under fire. For one thing, the DA just made up credentials for a crime scene photographer and had him testify to being a blood spatter analyst and the jury had no idea he didn't know what he was doing. Second, the sources you cited here testified on both sides of the case. Bevel testified for the prosecution that it was from a gunshot. Paul Kish, Barton Epstein, Paulette Sutton and Stuart H. James testified for the defense. Rod Englert, who is also a big name testified for the prosecution. It's one thing to say that BPA is a respected, reliable science, but I fear that people reading the article will not understand that there is variation within the field and it's not always easy for the jury to tell who applied the science correctly and who didn't, making it less reliable as a source of evidence.Bali88 (talk) 22:57, 8 February 2014 (UTC)

Also, I think it would be helpful to add the history of bloodstain pattern analysis as well as examples of how it is used in court. :-) Bali88 (talk) 01:06, 9 February 2014 (UTC)

NPOV

"There are many examples where some expert has gone off the deep-end with wild statements of “fact” that any reasonable person would find hard to believe."

1. pretty self explanatory I think. EMT1871 04:17, 23 January 2007 (UTC)

if such an example can be cited, it seems perfectly fine to me —Preceding unsigned comment added by 160.5.225.172 (talk) 01:11, 7 January 2008 (UTC)

NAS report

The National Academy of Sciences recently prepared a report to congress regarding the strength and weaknesses of several forensic sciences, including blood stain analysis. This report, along with the responses of SWGSTAIN and other organizations should be included. — Preceding unsigned comment added by 159.233.97.211 (talk) 17:38, 24 September 2013 (UTC)

Cleanup

I'm going to try and do a bit of a cleanup of this article. Large sections of text are likely to be removed.

The whole "Blood" section reads like the summary for a BPA introductory course, rather than an encyclopedia entry on it. Not to mention that the only reference used in it is for a bit of text that has basically been copy-pasted from the reference: Upon exiting the body, bloodstains transit from bright red to dark brown, which is attributed to oxidation of oxy-hemoglobin (HbO2) to methemoglobin (met-Hb) and hemichrome (HC). The fractions of HbO2, met-Hb and HC in a bloodstain can be used for age determination of bloodstains. I wonder what else in here might have been quoted verbatim from somewhere else. See MOS:QUOTE.

Then we see no references whatsoever on the following sections until the end of the "Area of origin" section, and no references are given again in the Photography section. Most of these sections also read like we're trying to teach people how to do BPA rather than writing an encyclopedia entry. Most of the information in the Photography section, especially, have no reason for being in this article. VdSV9•♫ 22:17, 16 December 2018 (UTC)

Factually incorrect information in this article.

I recently got done completing a Capstone paper on the reliability of Bloodstain Pattern Analysis. In that paper, I used both the ProPublica article and the NAS report that this page cited. This article states that Propublica article says that Bloodstain Pattern Analysis is never reliable in court. However, multiple studies, as well as the NAS report, say that some Bloodstain Pattern Analysis techniques are trustworthy. I was wondering if it would be okay for me to rewrite a sentence or two in the criticism section to reflect this. Scorpions13256 (talk) 08:57, 7 September 2020 (UTC)

Go for it, provided that you're accurately representing the scientific consensus across the sources. _signed, Rosguill ^talk 17:24, 7 September 2020 (UTC)

Done. Let me know if my edit was problematic though. Scorpions13256 (talk) 22:47, 8 September 2020 (UTC)

Wiki Education assignment: Seminars in Forensic Science

This article was the subject of a Wiki Education Foundation-supported course assignment, between 9 January 2023 and 6 April 2023. Further details are available on the course page. Student editor(s): Kira&Oscar (article contribs).

— Assignment last updated by Kira&Oscar (talk) 17:58, 21 March 2023 (UTC)

Poor main picture?

The "Examples of Blood-Spatter and Droplet patterns" picture does a bad job explaining everything. For instance what does the angle in "This is 90 degrees with no direction" mean? "Spine" and "Satellite" appear to be labelled the wrong way round. Someone please provide a much better picture from an authoritative source. 2A02:C7C:5690:A000:1629:F7D4:2391:3E93 (talk) 16:09, 8 March 2024 (UTC)

Wiki Education assignment: Seminars in Forensic Science

This article was the subject of a Wiki Education Foundation-supported course assignment, between 8 January 2024 and 30 April 2024. Further details are available on the course page. Student editor(s): Alind123 (article contribs). Peer reviewers: Jsoumis, Ejeann.

— Assignment last updated by Ejeann (talk) 22:20, 15 April 2024 (UTC)