Tucson Police Department dispatchers record each immigration check an officer makes over the radio. Officers are instructed to verify immigration status anytime they suspect someone they’ve stopped for another reason to be in the country illegally as well as anytime they arrest someone. The data include checks done in July and August 2013.
The color-encoded hexagons show the number of checks per unit area of about 0.13 square mile. The data are divided into 8 classes by Jenks natural breaks classification method. This classification provides an accurate representation of data’s spatial attributes.
The largest cluster of checks took place near Santa Rita Park where drug and alcohol have been problems, according to the police.