1. A police investigation to determine the perpetrator
   - detection, detecting, detective work

1. Watch, observe, or inquire secretly
   - spy, stag, snoop

Type of: monitor, police investigation, police work, supervise

Encyclopedia: Sleuth

• male monarch
• male offspring
• male orchis
• male orgasm
• male parent
• male pattern baldness
• male person
• male plug
• male reproductive gland
• male reproductive system
• male sibling
• male-patterned baldness
• maleate
• maleberry
• Malebranche
• Malecite
• maledict
• malediction
• malefaction
• malefactor
• malefic
• maleficence
• maleficent
• maleic acid
• malemute