Key Concepts

  • Blood spatter analysis looks at the size, shape, and direction of bloodstains to determine how the blood impacted the surface, and draws conclusions about how the crime likely occurred.
  • Blood spatter analysis has been accepted as reliable and admissible in North Carolina courts for many years, but reliability issues raised in recent cases could impact that admissibility determination in the future.
  • North Carolina’s appellate courts have not yet ruled on the admissibility of blood spatter analysis under amended Rule 702 and Daubert, but other trial courts using this standard have continued to admit such evidence.


Blood spatter analysis (or bloodstain pattern analysis) is a forensic technique in which stains of blood at a crime scene are examined to provide information about the incident, such as how or where the victim was killed. Blood spatter analysis includes the process of examining blood that has struck a surface, and applying knowledge regarding the characteristics of blood and the shapes or patterns made by its impact, in order to determine things like the direction, angle, and speed of its flight prior to impact, and, ultimately, to assist in reconstructing events that occurred in connection with the crime. 

The study involves detecting, describing, and analyzing the size, shape, distribution, number, location, and pattern of bloodstains, as well as the nature of the surface where the blood landed (“target surfaces”), and the relationship among various bloodstains at the scene. Potential target surfaces can include virtually any surface capable of sustaining detectable bloodstains – the victim, the victim’s clothing, the suspect, the suspect’s clothing, any weapon(s), any vehicle(s), or any other surfaces, such as walls, floors, or ceilings. See generally Aaron D. Gopen & Edward J. Imwinkelried, Bloodstain Pattern Analysis Revisited, 45 No. 3 CRIM. L. BULL. ART. 7 (2009). 

Admissibility and Reliability

In several cases decided under the Howerton standard that preceded the amendment of Rule 702 in 2011, North Carolina courts found bloodstain or blood spatter analysis to be a sufficiently reliable area for expert testimony. See, e.g., State v. Goode, 341 N.C. 513 (1995) (rejecting the defendant’s argument that bloodstain pattern interpretation has not been established as a scientifically reliable field, and rejecting the defendant’s argument that agent did not have sufficient qualifications to testify as an expert in the field); State v. Bruton, 165 N.C. App. 801 (2004) (citing Goode and holding that the trial court did not err by allowing an expert in forensic serology to testify regarding the nature of blood spatter over the defendant’s challenge to her qualifications as an expert); see also State v. Duke, 360 N.C. 110 (2005) (“A blood spatter and stain expert testified for the State during trial and shed further light on the brutality of the killings.”); State v. Morgan, 359 N.C. 131 (2004) (“Defendant's clothes were seized at the time of his arrest in November 1997, and the State conducted blood spatter testing on the clothing,” and the “preliminary blood spatter reports tied him to the murder”); State v. Davis, 202 N.C. App. 373 (2010) (unpublished) (no abuse of discretion in allowing expert at trial to give “testimony describing possible explanations for the absence of blood splatter” on a firearm); State v. Cherry, 186 N.C. App. 472 (2007) (unpublished) (“On the evidence before it, the trial court did not abuse its discretion when it decided to qualify Ms. Elwell as an expert in the field of blood spatter analysis”).

Practice Pointer

Recent problems 
If a prosecutor intends to use bloodstain/blood spatter evidence at trial, he or she will need to be prepared to respond to defense arguments questioning whether the case precedent cited above is still applicable, and attacking the qualifications of the case agent, the standards followed by the laboratory, and the validity of the field in general. In particular, the defense will likely raise the issue of a former SBI agent who frequently testified for the state as an expert witness (and trained other agents on how to conduct blood spatter analysis), but was later publicly discredited in several high-profile cases. See State v. Peterson, 228 N.C. App. 339 (2013), review denied, 367 N.C. 284 (2013) (new trial granted where state’s expert witness misrepresented his qualifications and methods). 
As a result, the defense may ask for a Daubert hearing to challenge the reliability of any proposed blood spatter testimony. To prevail on admissibility, the prosecutor should be prepared to explain why any errors or misrepresentations seen in past cases do not undercut the training, analysis, and conclusions of the agent in the present case. The Scientific Working Group on Bloodstain Pattern Analysis ("SWGSTAIN") has a helpful resource guide with suggested qualifying questions for an admissibility hearing.  

North Carolina's appellate courts have not yet addressed the admissibility of blood spatter evidence under Daubert or revised Rule 702. However, courts in several other jurisdictions have continued to allow blood spatter testimony at trial under the Daubert standard. See, e.g., Waller v. City of Fort Worth, 2018 WL 1757779 (N.D. Tex, Apr. 12, 2018) (court granted summary judgment in a civil case on other grounds, but noted in its discussion that “Hueske appears to be highly qualified to give his expert opinion on blood spatter and crime-scene reconstruction” and the witness’s report “may assist a factfinder in determining what likely happened in the garage”); U.S. v. Holt, 46 M.J. 853 (Navy-Marine Ct. Crim. App. 1997) (“We further note that blood-spatter analysis is admissible scientific evidence in military jurisprudence,” and finding that expert testimony on spatter patterns and luminol testing was admissible “even under a post-Daubert analysis”); see also Harrington v. Richter, 562 U.S. 86 (2011) (noting that “one of the detectives who investigated the shootings testified for the prosecution as an expert in blood pattern evidence” and denying defendant’s ineffective assistance of counsel claim based on failure to present any defense experts in response); Hedrick v. True, 443 F.3d 342, fn. 9 (4th Cir. 2006) (denying habeas petition, court noted that at trial “the blood spatter expert testified to the effect that Crider's body must have been moved after she was killed); Tinsley v. Million, 399 F.3d 796 (6th Cir. 2005) (denying defendant’s ineffective assistance claim that his counsel failed to adequately counter prosecution’s blood spatter expert, remanding on other grounds); Hamilton v. Workman, 217 Fed. Appx. 805 (10th Cir. 2007) (unpublished) (rejecting ineffective assistance where defense blood spatter expert testified to results which favored the prosecution). 

Portions of this entry were excerpted from the North Carolina Superior Court Judges’ Benchbook, “Criminal Evidence: Expert Testimony,” Aug. 2017, Jessica Smith.