HOUSTON -

Children all over town are trying to find just the right costume to score candy this Halloween. But before their little hands go knocking on doors, the Houston Police Department is making sure sex offenders won't be answering.

"We are letting all of them know that we are out there and we are watching them and will be checking on them," said Sgt. Glenn Shepherd with HPD's Juvenile Sex Offender Registry Unit.

Shepherd and his partner, Shari Waters, along with a crew of Houston officers, will be paying a visit to the 4,500 sex offenders registered in the city limits.

For the 2,400 offenders who committed crimes against children, Halloween comes with a laundry list of don'ts. There is no decorating the outside the house, no answering the door to children or passing out candy and no going to Halloween parties children will be attending.

"Those guys that are on probation and parole know there are conditions in the city of Houston, one of them being they cannot have any type of decoration that would lure a child to them," said Shepherd.

For the other men and women on the registry not on probation or parole, the best the officers can do is give a piece of advice. An offender at home and in compliance asked about going to his night job during the Halloween weekend.

"We just advise you to try not to have any interaction with any children, but you can go to work. You can go about your normal function because you are not on probation or parole," said Shepherd.

In Texas, only the offenders on probation and parole can have Halloween restrictions placed on them. Officers use this week to not only check on the decor outside of the house, but to make sure all offenders are living at the address on the registry.

"All of them have to have the same duty as far as law is concerned, and the law says they must notify us where they live at and they must notify us if they change their address," said Shepherd.

Out of the six homes Shepherd went to with a Local 2 camera crew, only half of the offenders were at home and living at the house listed on the registry. For those not where they are supposed to be, witness statements were taken, an investigation was opened and eventually an arrest warrant will be issued.

"We find them not in compliance, it is zero-tolerance. We are going to put them in jail," said Shepherd.

For parents worried about their kids going to the wrong house, there are several smart phone and tablet applications to help spot offender houses while walking your trick or treat path. Two of the highest rated are Life360's Sex Offender Search and BeenVerified's Sex Offender Tracker. Both applications have an icon on a map where an offender is listed on the registry. When used on a mobile device, you can see in real-time where you are walking in relation to the listed addresses. When you click on an icon, a picture with the address and charge pops up. Life360 has a companion app that lets you follow several phones, so you can track your child or children as they move through the neighborhood.

Shepherd warned parents to remember that a majority of attacks on children are done by someone the child or family knows, or by someone who is not on the registry at all.

"There is a way to check and see who is a sex offender in your neighborhood, but the problem we have is that not all sex offenders are on the list. Another problem is they come from out of state and merge into our society as homeless, and they are out there. Those are the guys we should be more concerned about, that we don't know are there," said Shepherd.

When it comes to sending your children out in groups this Halloween, make sure there are two adults going out with every bunch of princesses and vampires, no matter what their age.

How many sex offenders have to follow the Halloween rules? Here are the numbers of offenders who fall into this category, grouped by Houston Police Department's risk levels.

  • Highest risk -- (civil commitment) 34 out of 46 are on probation or parole
  • High risk -- 225 out the 509 are on probation or parole
  • Moderate risk -- 742 out of 1774 are on probation or parole
  • Low risk -- 407 of the 886 are on probation or parole
  • Not assigned a risk level -- 219 out of 1294 are on probation or parole