First Aid, CPR, and Scene Medical Emergencies

Why First Aid and Emergency Response Matter at a Crime Scene

Crime scene technicians work in unpredictable environments: abandoned buildings, outdoor terrain in extreme heat, active roadways, and locations where hazardous chemicals or biological material may be present. A medical emergency can strike a colleague, a bystander, or you. Knowing how to respond correctly—and quickly—can be the difference between life and death. This lesson prepares you to perform hands-only CPR, use an automated external defibrillator (AED), and apply first aid to the most common field emergencies forensic technicians face.

Cardiac Arrest: Hands-Only CPR and AED Use

Sudden cardiac arrest stops the heart's ability to pump blood. Brain damage begins within minutes without circulation. The chain of survival—early recognition, calling 9-1-1, early CPR, early defibrillation, and advanced care—saves lives when each link is strong.

Hands-Only CPR steps:

1. Confirm the scene is safe before approaching.

2. Tap the victim's shoulders and shout to check responsiveness.

3. Call 9-1-1 (or direct a bystander to call) and send someone for the AED.

4. Position the heel of one hand on the center of the chest (lower half of the breastbone), place the other hand on top, and interlock fingers.

5. Push hard and fast—compressions should be at least 2 inches deep for adults and delivered at a rate of 100–120 compressions per minute. Allow full chest recoil between compressions.

6. Continue without interruption until the AED arrives, EMS takes over, or the victim shows obvious signs of life.

AED use:

1. Power on the AED and follow its voice prompts.

2. Attach pads to bare, dry skin: one pad below the right collarbone, one to the left side of the chest below the armpit.

3. Clear everyone from the victim and allow the AED to analyze the rhythm.

4. Deliver a shock if advised, then immediately resume CPR starting with compressions.

5. Continue CPR and AED cycles until EMS arrives.

Wear gloves whenever you contact a victim's body fluids. A face shield is required if rescue breaths are given.

Sharps Puncture: What to Do Immediately

Forensic technicians encounter hypodermic needles, broken glass, knives, and other sharps at scenes. A puncture or cut carries risk of bloodborne pathogen exposure (HIV, hepatitis B, hepatitis C).

Immediate response:

1. Remove contaminated gloves carefully using a glove-to-glove, skin-to-skin technique to avoid self-contamination.

2. Wash the wound with soap and running water for at least 15 minutes. Do not squeeze the wound or apply caustic agents.

3. Report the exposure to your supervisor immediately.

4. Seek medical evaluation without delay—post-exposure prophylaxis (PEP) for HIV must begin as soon as possible after exposure and within a defined time window.

5. Complete your agency's post-exposure control plan and incident report accurately, recording the time, object involved, location, and first aid steps taken.

OSHA's Bloodborne Pathogens Standard (29 CFR 1910.1030) requires employers to have an exposure control plan and to offer a confidential medical evaluation after any occupational exposure incident.

Chemical Exposure: Skin and Eye Contact

Forensic reagents such as ninhydrin, luminol activators, and cyanoacrylate (superglue) fuming agents can irritate or injure skin and eyes. Always consult the Safety Data Sheet (SDS) for the specific chemical involved.

Skin exposure:

• Remove contaminated clothing and PPE without spreading the chemical.
• Flush the affected skin with large amounts of water for at least 15–20 minutes at an emergency eyewash or drench shower.
• Seek medical attention if irritation persists or if the SDS directs it.

Eye exposure:

• Immediately flush the eye with clean, lukewarm water for at least 15 minutes, holding the eyelid open.
• Remove contact lenses after the first minute of flushing if it can be done easily.
• Do not rub the eye.
• Seek emergency medical evaluation after flushing; bring the SDS or chemical label.

Emergency eyewash stations must be accessible within 10 seconds of chemical work areas per ANSI/ISEA Z358.1.

Heat Stress Emergencies

Technicians in personal protective equipment or working in summer heat are at real risk for heat exhaustion and heat stroke.

• Heat exhaustion: Heavy sweating, weakness, cool/pale/moist skin, nausea, headache. Move victim to a cool area, loosen clothing, apply cool wet cloths, and give cool water if alert.
• Heat stroke (life-threatening): High body temperature (above 103°F), hot/red/dry or damp skin, confusion, possible loss of consciousness. Call 9-1-1 immediately. Cool the victim rapidly with ice water immersion or cold wet towels to the neck, armpits, and groin while waiting for EMS. Do not give fluids to an unconscious person.

Documenting Every Incident

Accurate documentation is a professional and legal requirement. Your incident report must include: date, time, and location of the incident; names of those involved; a description of what happened; first aid steps taken and by whom; and the reporting chain followed. Missing required fields can jeopardize workers' compensation claims, OSHA recordkeeping compliance, and any subsequent medical follow-up. Complete the form before leaving the scene whenever possible.

Your PPE Baseline in This Lab

For all hands-on activities in this lesson: nitrile gloves, eye protection (face shield during CPR with rescue breaths), and closed-toe shoes. Remove PPE in the correct order—outside surfaces are contaminated. Wash hands after every scenario.