Emails, Gaylene Armstrong, research director, the Correctional Management Institute of Texas, director, Criminal Justice and Criminology graduate programs, Sam Houston State University, July 25, 2014
I would direct you to the fbi.gov website that posts the Uniform Crime Reports (UCR). These statistics are based on official reports of crime to local police departments. They are viewed as a reliable source with the understanding that not all persons report all crimes that occur. See specifically Table 4 located here:
Senator Hinojosa is correct but an important point should be kept in mind that I will explain - If you consider a specific city in the Rio Grande area (e.g., Brownsville), certainly there are FEWER crimes reported to police than what would occur in a larger metropolitan area (e.g., Dallas). I would expect this to be true even if you were able to account for crimes that occur and go unreported and therefore not included in the UCR. The point to be aware of is there is a significantly greater population in such urban areas and one would really need to compare the crime "rates," which accounts for the number of crimes occurring as well as the number of people in the city.
The Senator is likely correct in his statement - the UCR indicates there are fewer crimes in Brownsville than Houston or Dallas. There is no specific report of statistics for the "Rio Grande Valley" in the UCR so this is my best estimate. Considering either raw numbers or more appropriately rates, the outcome is the same:
To calculate a rate, divide the raw number of crimes in which you are interested (e.g., violent crime) by the population of the city. Multiply that value by 100,000. The result will give you the number of crimes (e.g., violent crime) per 100,000 people in that particular city.
For example - Violent Crime comparison between Brownsville and Houston using 2012 since that is the last FULL year of crime statistics computed at this time
Brownsville: (248 / 181,102) * 100,000 = 136.9 violent crimes per 100,000 people
Houston: (10,719 / 2,177,273) * 100,000 = 492.3 violent crimes per 100,000 people
This should clarify my earlier information. I do not see anything else to consider in verifying the Senator's statement