The Profile of a Sex Offender
It is smart to do an online search with companies, such as Veromi, if you suspect a person is a sex offender. Especially if that person will be spending time around your children. That is because sex offenders come in many shapes and sizes and are not always obvious. 

Here is some information, which may be surprising, about sex offenders, courtesy of childluresprevention.com:

• Approximately 400,000 convicted pedophiles currently live in the United States. On average, that's one per square mile.
• Sex offenders are not all shady-looking men. They are also women, young adults, middle-aged adults and seniors. They are upper class, middle class and disadvantaged. They are from all races and ethnicities and all job fields.
• Male offenders who abuse girls average 52 victims each; male offenders who abuse boys average 150 victims each.
• Sex offenders find their prey by befriending parents, especially single parents, to gain access to their children; offering babysitting services to overextended parents and caregivers; taking jobs and participating in community events that involve children; volunteering in youth organizations; loitering in places children frequent such as parks, playgrounds and arcades; becoming foster parents; and spending time in online gaming communities learning child lingo.
• Most sex offender victims are "groomed" over a period of weeks, months or years. The "affection lure" is used both offline and online to seduce unsuspecting children in need of love and attention. Child molesters have repeatedly reported that a physically or emotionally absent parent makes the child more vulnerable than ever.
• Children on the brink of puberty are targeted most often because it is easy for sexual predators to prey on the sexual curiosity and ignorance of them.
• Kids and teens sexually abuse children younger than them. Many juvenile offenders are victims of sexual abuse themselves.
• Facts about pedophiles: they are notoriously friendly, nice, kind, engaging and likeable; they target their victims, often insinuating themselves into that child's life – their family, school, house of worship, sports, and hobbies; they are professional con artists and are expert at getting children and families to trust them; and they will smile at you, look you right in the eye and make you believe they are trustworthy.