What Happens During a Professional Crime Scene Clean?

You’ve probably never had to think about this before. Most people haven’t. But now you’re here, and you need to know what happens next.

I’ll tell you exactly what we do, step by step, so there are no surprises. After 25 years of this work, I know that understanding the process helps. It takes away some of the uncertainty during a time when everything feels uncertain.

Before We Arrive: Assessment and Planning

The process starts with your phone call. Here’s what happens on our end before we even get to the property.

The call itself. You’ll speak to someone from our team directly. Not a receptionist. Not a call centre. We’ll ask some questions, but only what we need: the type of incident, the property size, whether police have released the scene, and access details. We won’t ask for graphic details. We don’t need them at this stage.

Key collection. If you’d rather not be at the property when we arrive, we can collect keys from you, a neighbour, a letting agent, or the police. Many families choose this option. That’s completely fine.

Unmarked vehicles. Our vans carry no branding that identifies the nature of our work. When we pulled up to a terraced house near Gloucester Road last spring, the neighbours assumed we were decorators. That’s deliberate. Your privacy matters, and the last thing you need is people asking questions you’re not ready to answer.

PPE and equipment. Before we leave our base on Southmead Road, we load specific equipment based on what you’ve told us. Full PPE for the team. Specialist biohazard cleaning agents. HEPA filtration. Enzyme-based cleaners. Sealant products. Everything we need to do the job properly in one visit where possible.

Timing. We can typically be on site within 2 to 4 hours across Bristol and surrounding areas. For emergencies, call our 24/7 line on 0808 303 7072.

Phase 1: Site Assessment

We don’t just walk in and start cleaning. The first thing we do is assess.

This takes between 30 minutes and an hour depending on the property. We’re looking at:

• The extent of contamination. Where are the affected areas? Has anything spread beyond the obvious?
• Surface types. Carpet, hardwood, tile, plaster, concrete. Each one needs a different approach. Blood behaves differently on porous versus non-porous surfaces, which we cover in our blood cleanup guide.
• Structural penetration. Has contamination seeped into floorboards, subfloor, wall cavities, or between ceiling layers?
• Ventilation. What airflow does the property have? This affects our odour treatment strategy.
• Items for disposal. What can be cleaned and saved? What needs to go?

We document everything with photographs. If you’re making an insurance claim, this documentation is important. We work with insurers regularly and know what they need to see. More on that in our insurance guide.

At this point, we’ll give you a fixed price. No hidden extras. The price we quote is the price you pay.

Phase 2: Removal and Decontamination

This is the main work. Depending on the severity, this phase takes anywhere from 4 hours to several days.

Removal of contaminated materials. Anything that can’t be safely decontaminated gets removed. That might include carpet, underlay, sections of flooring, soft furnishings, mattresses, or plasterboard. We bag everything in clinical waste bags, labelled and sealed according to hazardous waste regulations.

We try to save what we can. Honestly, that matters to families. A carpet is just a carpet. But sometimes it’s the sofa their mum sat in every evening. If we can clean it safely, we will. If we can’t, we’ll tell you straight.

Hard surface decontamination. We use hospital-grade disinfectants and biocidal agents on all hard surfaces. This isn’t a quick wipe down. We’re working at a cellular level to break down biological material and eliminate pathogens.

Blood-borne viruses like Hepatitis B can survive on surfaces for up to 7 days. HIV is less hardy but still presents a risk in the right conditions. Hepatitis C can persist for weeks. This is why you should never attempt this yourself with household products. The risk is real.

Porous surface treatment. Walls, unsealed wood, grout, and concrete need deep treatment. Biological fluids penetrate porous materials quickly. We use specialist products that draw contamination out from within the material, not just clean what’s visible on the surface.

Waste disposal. All biohazardous waste is disposed of through licensed clinical waste contractors. We hold the correct waste carrier licences and provide a full audit trail. This matters legally. Biological waste cannot go in normal bins or skips. It’s categorised as hazardous waste under UK regulations.

Phase 3: Odour Elimination

This is the phase people don’t think about until they notice it. Biological contamination produces odours that household air fresheners and even industrial cleaning won’t touch.

We use a combination of approaches:

Ozone treatment. Ozone generators produce O3 molecules that break down odour-causing compounds at a molecular level. We seal the affected rooms and run generators for a set period. The property needs to be unoccupied during this phase. Ozone is effective but needs careful handling.

Thermal fogging. A fine fog of deodorising agent penetrates every crack, crevice, and porous surface. It reaches places liquid cleaning can’t. Behind skirting boards. Inside wall cavities. Into ceiling voids.

HEPA air scrubbing. High-efficiency particulate air filtration removes airborne contaminants and particles. We run these during and after the cleaning process.

Sealant application. In some cases, we apply specialist sealants to subfloor, concrete, or other structural surfaces. This locks in any residual odour that sits deep within the building fabric. Think of it as a barrier between the contamination history and the fresh surfaces that will go on top.

This phase can take 24 to 48 hours. Rushing it doesn’t work. If the odour comes back a week later, we haven’t done our job. We make sure it’s gone properly the first time.

Phase 4: Verification and Handover

We don’t just finish and leave. The final phase is about making sure everything is right.

Visual inspection. Every treated surface gets checked under normal and UV light. Biological residue fluoresces under ultraviolet light. If it glows, it’s still there. We treat it again.

ATP testing. Adenosine triphosphate testing gives us a measurable reading of biological contamination on surfaces. It’s the same technology used in hospitals. A clean surface gives a reading below a set threshold. If it’s above, we re-treat.

Odour verification. We check every room, every corner, every enclosed space. Cupboards. Airing cupboards. Under stairs. Odour can hide in surprising places.

Documentation. You’ll receive a full report covering what was done, what was removed, waste transfer notes, and before-and-after photographs. If your insurer needs anything else, we handle that directly. We deal with insurance companies every week.

Handover. We’ll walk you through the property if you want us to. Some people prefer a phone call instead. Either is fine. We’ll explain what was done, flag anything that needs further attention (like replacing flooring or redecorating), and answer any questions.

The property is left clean, safe, and habitable. Not just looking clean. Actually clean, at a biological level.

What We Don’t Do

We’re honest about our limits.

We don’t provide counselling or emotional support beyond basic human decency. But we can connect you with Victim Support (0808 168 9111) and other Bristol-based services.

We don’t do structural repairs, redecoration, or refurbishment. But we can recommend trusted tradespeople in Bristol who we’ve worked alongside for years.

We don’t pressure you into decisions. If you need a day to think about it after our assessment, take it. The quote won’t change.

Getting Started

Call us on 07985 505061 or our 24/7 emergency line on 0808 303 7072.

Email hello@bristolcleaningheroes.co.uk if you’d rather put it in writing first.

We’re at 290-294 Southmead Road, BS10 5EN. £2 million insured. 25 years’ experience. Unmarked vehicles. Discreet, compassionate, and thorough.

If you’re worried about cost, read our guide on who pays for crime scene cleaning in the UK. There are more options than you might think.