The first step of a forensic autopsy is the external examination: before any incision is made, the pathologist inspects and documents the body’s outer surface, clothing, injuries, and identifying features. That hands-on exam, though, is not where the case actually begins. By the time the body reaches the examination table, it has already been sealed at the scene, transported under a documented chain of custody, and the pathologist has reviewed the police reports, medical history, and circumstances of death that will shape what to look for.
So the honest answer has two layers. The first physical step on the body is the external exam. The first procedural step of the case is intake and review.
What Happens Before the Pathologist Touches the Body
Two things have to happen before the external exam can begin: the body has to arrive intact, and the pathologist has to know the context.
At the scene, the deceased is placed in a sealed body bag or evidence sheet to prevent contamination during transport to the morgue. Every person who handles the body or any associated evidence is logged. That log is the chain of custody, a written record proving the evidence has not been tampered with, and it follows every item from collection through storage, testing, and court presentation.1NCBI Bookshelf. Chain of Custody Each transfer requires signatures, dates, and a description of how the evidence was stored. A break in that chain can make evidence inadmissible at trial, so forensic facilities treat the documentation as one of the most critical parts of the process.2National Institute of Justice. Law 101 Legal Guide for the Forensic Expert – A Chain of Custody: The Typical Checklist
The pathologist also reviews all available information before starting the exam. Police reports, witness statements, the decedent’s medical history, and the circumstances at the death scene all shape what to look for. A death involving a fall focuses attention on skeletal trauma. A suspected poisoning shifts the emphasis toward toxicology sampling. Walking into the exam room with that context is what separates a routine examination from one that catches the details that matter.
The External Examination Itself
Once the body is on the table and the paperwork is in order, the external examination begins. It follows a strict sequence set out in professional standards from the National Association of Medical Examiners.
The pathologist starts with the clothing, before removing it. The condition, position, and any damage are documented first, because tears, bullet holes, bloodstains, and powder residue on clothing can tell a story the body alone cannot.3National Association of Medical Examiners. Forensic Autopsy Performance Standards Only then is the clothing removed and bagged.
Next, the pathologist measures and records body length and weight, then inspects every surface of the body. Identifying features such as tattoos, scars, birthmarks, and surgical scars are cataloged. Each injury is classified by type, location, size, shape, and color. The standards require inspection of the head, neck, chest, abdomen, genitals, extremities, and the entire back of the body.3National Association of Medical Examiners. Forensic Autopsy Performance Standards
Reading Postmortem Changes
The external exam is also where the pathologist evaluates postmortem changes to estimate when death occurred.
Rigor mortis, the stiffening of muscles after death, generally appears within one to two hours, fully develops by about 12 hours, holds for another 12 hours, and then gradually fades. It follows a head-to-toe progression, starting with the eyelids and jaw before reaching the fingers and toes.4NCBI Bookshelf. StatPearls – Postmortem Changes
Livor mortis, the settling of blood into the body’s lowest points after circulation stops, produces visible discoloration. Patches begin appearing within one to three hours, spread over the next several hours, and become fully developed within six to eight hours. The pathologist uses a blanching test, pressing a thumb into the discolored area, to determine whether the lividity is still shifting or has become fixed. Fixed lividity means the blood has coagulated in place, which happens roughly six to eight hours after death. If the lividity pattern does not match the position the body was found in, that is a red flag that the body was moved after death.4NCBI Bookshelf. StatPearls – Postmortem Changes
These timelines are rough estimates, not precise clocks. Temperature, body composition, and environmental conditions all affect the speed of postmortem changes, so experienced pathologists give a range rather than a specific time of death.
Confirming Identity
The pathologist also confirms the identity of the deceased during the external exam. In straightforward cases, that means checking identification tags against case records. When visual identification is not possible because of decomposition, burns, or other disfigurement, fingerprints, dental records, or DNA testing may be needed to establish identity.
Documenting and Collecting Evidence as the Exam Proceeds
Documentation runs alongside the external exam, not after it. Every finding is recorded through written notes and photography. Photographs capture overall views of the body first, then close-up images of each injury or identifying mark. A measurement scale is placed next to wounds and other significant features for accurate sizing. Autopsy photography follows standardized procedures so the visual record holds up as objective evidence in later legal proceedings.5National Institute of Standards and Technology. Standard Guide for Post Mortem Examination Photography
Physical evidence is collected at the same time. Trace evidence such as fibers, dirt, glass fragments, and hair is removed from the body and clothing. Fingernail clippings or scrapings are collected, along with swabs of bodily fluids. In suspected sexual assault cases, the standards call for oral, vaginal, and rectal swabs, pubic hair combings, and collection of any foreign hairs or fibers.3National Association of Medical Examiners. Forensic Autopsy Performance Standards Each item goes into a separate, labeled container. Clothing is packaged individually in paper bags to prevent deterioration and cross-contamination. Every container is signed, dated, and timed to maintain the chain of custody.6NCBI Bookshelf. StatPearls – Evidence Collection
When foul play is suspected, pathologists also collect DNA swabs from areas of the body where an assailant may have left biological material. These swabs can yield DNA profiles suitable for comparison against suspects or for upload into the FBI’s Combined DNA Index System. Timing is critical: once the body has been cleaned and prepared for release, the opportunity to recover this evidence is gone.7Federal Bureau of Investigation. Body Swab DNA Collection in Death Investigations
Imaging and Toxicology Before Any Incision
Before any cut is made, the pathologist may order X-rays or CT scans of the body. Imaging helps locate bullets, knife fragments, or other foreign objects embedded in tissue, and it reveals fractures and skeletal abnormalities that are not visible on the surface. In some facilities, full-body CT scanning is routine, providing a detailed three-dimensional map of the body’s interior before dissection begins.
The concept of a “virtual autopsy” uses CT, MRI, and 3D surface scanning to examine the body with minimal or no physical intrusion. These techniques show about 80 percent agreement with conventional autopsy findings on cause of death, and they are particularly effective for detecting fractures, trauma patterns, and structural defects. They are less reliable for identifying infections, tumors, and subtle soft-tissue conditions, so they have not replaced traditional dissection.8National Center for Biotechnology Information. Virtopsy: An Integration of Forensic Science and Imageology Virtual autopsy techniques are increasingly used alongside conventional methods and offer a partial alternative when religious or cultural objections make traditional dissection especially sensitive.
Toxicology specimens are collected at this stage as well. Blood samples from specific sites, urine, and vitreous humor (the fluid behind the eye’s lens) are the standard trio. Each serves a different purpose. Blood provides quantitative drug and alcohol levels. Urine is particularly useful for screening for unknown drugs of abuse. Vitreous humor helps assess conditions like diabetic ketoacidosis. Keeping blood samples from different collection sites separate matters because drug concentrations can vary significantly depending on where in the body the sample was drawn.
Only once the external exam, documentation, evidence collection, imaging, and toxicology sampling are complete does the pathologist move on to the internal examination.
When a Forensic Autopsy Is Ordered in the First Place
Not every death leads to a forensic autopsy, so none of the above happens unless the case qualifies. Medical examiners and coroners order forensic autopsies when the cause or circumstances of a death are unclear, suspicious, or potentially criminal. That includes sudden or unexpected deaths, suspected homicides, suicides, drug-related deaths, deaths in police custody, workplace fatalities, and cases where medical negligence is alleged.9NCBI Bookshelf. StatPearls – Forensic Autopsy In most jurisdictions, the medical examiner or coroner has legal authority to order the autopsy without family consent when the death falls into one of these categories.
If a death occurs from a known, documented illness under a doctor’s care, a forensic autopsy is almost never required. The line gets drawn at deaths where something is unexplained or where legal liability could be at stake.