How to become a crime scene investigator

Crime scene investigators (CSIs) are police staff employed by a force to examine scenes, find and recover forensic evidence, and record what they found so it can be used in court. You do not need to be a police officer, and most forces do not ask for one. The usual route is to apply for a trainee or CSI post with your local force, pass vetting, then complete initial training and supervised scene work before you work alone. Pay is set by the force on its police staff grades.

What CSIs do

Forces use different titles: crime scene investigator, crime scene examiner and scenes of crime officer all describe the same job. Most of the workload is volume crime, such as burglary, vehicle crime and criminal damage, where a CSI visits the scene, looks for fingerprints, footwear marks, DNA and fibres, and photographs and recovers what is useful. A smaller share is serious crime: sexual offences, serious assaults, suspicious deaths and murders, where scenes are larger, take days and are run with a crime scene manager in charge.

On a typical shift you might:

• attend several scenes, talk to the victim and decide what to examine
• dust and lift fingerprints, take swabs and recover items for the lab
• photograph scenes and exhibits to a set standard
• package and label exhibits so that the chain of custody holds
• write statements and update case records
• attend post-mortem examinations on serious cases

Some CSIs go on to specialise in areas such as fire investigation, forensic photography, footwear, fingerprint comparison or crime scene management.

The less pleasant parts

Most days are routine burglaries, and a great deal of time goes on paperwork and driving between jobs. The serious cases involve dead bodies, blood, decomposition and distressed families, sometimes involving children. Forces offer welfare support and trauma risk management, and you should think hard about how you would cope before applying.

CSIs work shifts that cover evenings, nights and weekends, and serious crime work involves on-call rotas. The job is physical: kneeling, lifting, working in protective suits for long periods and standing at outdoor scenes in all weather.

Qualifications and skills

Entry requirements vary by force. Common requirements include:

• a degree or qualification in a science subject, or relevant experience (forensic science, biology, chemistry and photography are common backgrounds)
• a full driving licence, because you drive yourself to scenes
• good written English, as your notes and statements go to court
• normal colour vision, which some forces test

You need close attention to detail, because a CSI who misses evidence or contaminates a scene can wreck a prosecution. You also need to deal kindly with burglary victims and calmly with officers who want quick answers.

Training and accreditation

New CSIs complete an initial course in crime scene examination, run by the force or a national provider, covering evidence recovery, photography, contamination control and court work. You then work under supervision and build a portfolio before being signed off for independent work. Serious crime work and specialist techniques come later, with further courses.

Crime scene examination in England and Wales falls within the quality standards overseen by the Forensic Science Regulator, which has statutory powers under the Forensic Science Regulator Act 2021. Forces need to show their scene work meets those standards, so expect regular competence checks, documented procedures and audit of your work.

Pay and pension

CSIs are police staff, so the force sets pay on its own staff grades. Outside London, forces use the Police Staff Council pay spine with local grading, and the Metropolitan Police has its own arrangements. Trainee posts are usually graded lower than qualified CSI posts, with progression once you are signed off. The advert gives the salary, and shift allowances and on-call payments are often added.

By mid October 2026 no police staff pay award for 2026/27 had been announced. The unions had claimed 9% or £2,700 from 1 September 2026, so check your force’s announcements for the outcome.

Police staff in England and Wales are in the Local Government Pension Scheme. For 2026/27 the main section member rate is 5.8% on pay from £18,401 to £29,000 and 6.5% on pay from £29,001 to £47,300. Local Government Pension Scheme explains the scheme, and the take-home pay calculator works out monthly pay from a salary.

Applying

Forces advertise CSI vacancies on their own careers pages, sometimes only once or twice a year. Applications are scored against the person specification, then shortlisted candidates usually have an interview and a practical or written exercise, such as describing how you would approach a scene from a photograph. Some forces include a colour vision test.

Before an offer is confirmed you go through police vetting, which looks at you, your finances and your close family and associates. Security clearance levels explains vetting more generally. Vetting and medical checks can take several weeks.

If you want investigative work without the forensic focus, police staff investigator covers the civilian route into investigating crime. PCSO is another police staff role that some people use to get to know policing before applying for a CSI post.

Scotland and Northern Ireland

In Scotland, scene examination is carried out by the Scottish Police Authority’s forensic services, not Police Scotland itself, and in Northern Ireland the PSNI employs its own scenes of crime staff. Both recruit separately.