While the Greater Katy area is estimated to have a population in excessive of 300,000, the current population of the actual city of Katy is only estimated to be around 18,000. That does include areas from 3 counties - Harris, Fort Bend and Waller.
Katy, Texas - Wikipedia
I am not sure if all the addresses of these 3 high profile crimes are considered to be within the city of Katy. My preliminary research indicates all are not. My humble opinion that these 3 murder cases seem like a lot for the area is based on the fact that they ARE high profile I guess.
Temple - 22592 Round Valley Drive, Katy, TX
Sheats - 6011 Remson Hollow Lane, Katy, TX
Perez - 3800 block of Silverhawk Drive, Katy, TX
Interesting to note that the Temple murder is scheduled to be retried in February 2019, some 20 years after it occurred.