Friday, May 9, 2014

One thing really well

Lincoln has a residency restriction for registered sex offenders who meet the definition of "sexual predator" in state law. Our local ordinance prohibits these offenders from living within 500 ft. of any K-12 school. The ordinance (9.16.250) specifies that this measurement is from the property line of the school to the property line of the parcel upon which the residence is located.

With some frequency, sexual predators subject to this restriction contact us trying to determine if a particular location is within or outside of the restricted area. They also contact the Sheriff's Office, the Parole Administration, and probably others trying to make this determination. It has always been a little tedious to do so, requiring a fairly good knowledge not only of the ordinance, but also a more-than-casual familiarity with the City's GIS viewer at its measuring tools.

It is now getting a whole lot easier. Andrew Dasher, the manager of the Lincoln Police Department's Crime Analysis Unit made a web mapping application yesterday, using ArcGIS Online. It is a application that allows a user to input an address, and quickly see whether it is within the 500 ft. buffer from nearby schools. While it's awfully good as is, he is in the process of working with Lincoln's GIS manager, Jeff McReynolds, to make it even better, so this app is likely to be slightly different in the future, and even more accurate.

Over the past few years, I've started to really appreciate these ArcGIS Online web mapping applications. They are easy to build (even a Director can do it) and quickly deployed. Previously, I used apps that contained dozens of layers and fulfilled many different purposes. Now I am drawn to simple applications that do one or two things really well. ArcGIS offers many templates, and web maps can be embedded in other sites.

We use one that is a very simple lookup for parcels, another that is a basic streetfinder, one that is a portal to the City's traffic cameras, another that locates Lincoln Fire & Rescue pre-plans, one that just looks up the correct police reporting district and zipcode for a specific address, and now this one--to discover whether an address is within 500 ft. of a school. A gallery of such web mapping applications (similar to Grapevine, TX), is a nice way of providing these tools either internally or to the public.


Steve said...

Is there any evidence to suggest that this ordinance has any effect on the number of sexual assaults on children? I'm not necessarily opposed to it, in fact I don't care if you kick the perverts out of town all together. I just wonder if the ordinance is anything more than a "feel good" effort by the city to make people think they are safer.

Tom Casady said...


No, there is no evidence that these restrictions have any impact on sexual assault of children. I worry, in fact, that residency restrictions might have unintended consequences that are not good. I think we primarily have such laws as a means of making people feel a little better about the ugly truth that there are over 500 convicted sex offenders living in our City, and tens of thousands around the country. Not that making people feel a little better is a bad thing (particularly when it is a minor inconvenience for the registered sex offender).

ARRRRG!!!! said...

I think Drew left my school off the map.

Anonymous said...

These laws are generally pushed in order to get pressure groups off the backs of elected officials. In other words, "something must be done, and this is something, so it must be done". Law passed, pressure group mollified and off the backs of the pols.