Businesses undertaking investigation and security activities provide services intended to gather information, protect people or property, and help manage security risks. Investigative work may include tracing people or assets, making discreet enquiries, checking information, conducting surveillance where lawful, and preparing reports for individuals, solicitors or organisations. Some firms specialise in particular areas, such as workplace investigations, fraud enquiries or background checks. Security services can include manned guarding, mobile patrols, door supervision, event security, key holding, alarm response, and monitoring of security systems. Some businesses also advise on security procedures, carry out risk assessments or provide secure transport for valuables. The work offered varies between providers, and not every business undertakes both investigation and guarding.