In a recent ruling, the Supreme Court of Colorado made it much more difficult for average police officers to testify about certain evidence in criminal trials. The court ruled that trial witnesses, including police officers, who have experience interpreting blood evidence in criminal cases cannot testify as “lay” witnesses, but rather must be qualified as “experts” before being allowed to testify.

People v. Ramos

In 2006, a man named Ruben Ramos was riding in the passenger seat of a vehicle driven by his girlfriend. His girlfriend’s three children were seated in the back, along with a friend of hers known only as R.L. R.L. testified that Ramos turned to her, used an offensive slur and physically assaulted her by punching her in the face and neck.  At the time of the assault, Ramos’s hand was bandaged and bleeding from a previous injury not tied to the incident. Some of the blood landed on R.L.’s clothing. Ramos defended his actions by arguing that he had not struck R.L and the blood stains landed where they did from waving his hands.

Two main pieces of evidence were presented at trial: R.L.’s testimony and a police detective’s testimony which was admitted as lay testimony despite the detective’s expertise in his interpretation of blood evidence. The jury convicted Ramos on both counts of committing a bias-motivated crime and assault in the third degree.

Lay Witness v. Expert Witness

In People v. Ramos, the  Colorado Supreme Court affirmed the court of appeal’s holding that the trial court “abused its discretion” by not qualifying the police detective’s blood testimony as expert testimony. The Court held that an ordinary person would not be able to testify confidently about the difference between blood that has been cast-off and transferred blood. The detective, who had investigated thousands of cases involving blood evidence over 19 years, would not be able to contribute the conclusions he drew without having his specialized knowledge.

The testimony of a police officer who testifies as a lay witness – rather than an expert – in situations where he has much more experience participating in criminal cases than the average citizen heavily influences a jury’s perception. Under Colorado Rule of Evidence 701, testimony is acceptable as lay testimony if it is “(a) rationally based on the perception of the witness, (b) helpful to a clear understanding of the witness’s testimony or the determination of a fact in issue, and (c) not based on scientific, technical, or other specialized knowledge.”

An expert witness is one who has specialized knowledge based on his education, training, or experience. To testify as an expert, a police officer must be qualified as such by the judge. Expert witnesses carry a great influence over a jury’s decision. To ensure your criminal case is handled by a dedicated Colorado defense attorney, call Miller Leonard, PC at 720-613-8783. With decades of experience trying criminal cases in Colorado, Miller Leonard seeks to protect your rights at every step of litigation. Get a free consultation today!


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