The difference between a security guard and a police [officer or force] is the ability to arrest and detain for legal infractions. A sworn (and deputized) peace

The difference between a security guard and a police [officer or force] is the ability to arrest and detain for legal infractions. A sworn (and deputized) peace officer may enforce the laws they are and have sworn to uphold regardless of if they are "on the clock" or being paid. Many security guards are often police officers working a second job.