What is a company that a forensic scientist can work?

You could work at a number of places/institutions:
Private Forensic Firms
Crime Laboratories
Coroner's / Medical Examiner's Officies
Police Dept. Forensic Teams
Law Enforcement Evidence Technicians
Companies that make products for forensic testing (Immunalysis, Agilent, Restek, etc.)
The FBI Forensic Science Divison
DEA (drug enforcement agency)
University as a professor in forensic field

you can work for the

- police as a forensic examiner or a Scene of crime officer - (these go to the crime scene to collect the evidence)

- Private forensic science companies - (you would work as a forensic scientist to examine evidence or be a forensic technician which is like a trainee forensic scientist)

- Government forensic science company - (as a forensic scientist to examine evidence)

- Pathologist - may work in a hospital or medical lab to determine the cause of death and take biological samples.

- Manufacturing company who makes field equipment such as preliminary drug detection kits, and blood testing kits.

i can't try to give specific names as i do not know what country you live in. i have been trying to find companies myself as i have just graduated with forensic science and found just googling forensic science company or forensic science jobs will bring up results of companies.

the best thing i would suggest is the police as there will probably be forensic jobs in each country