14 big rigs

I was driving home last night at 1am from Boulder City. Every time I drive home late I practically always imagine what Id do if I got pulled over.
The first thing I saw was a large cargo truck driving up Yucca street. Following it was a police vehicle.
I felt accomplished because I had immediately found what I was looking for on my way home, but there was more to this short escapade.
When I initially caught the policeman following the truck I had figured it had just gotten there due to the regular flow of traffic. However, at 1am the flow of traffic in Boulder City is the equivalent to a dried up river. I couldn't help but envelop myself into this miniscule mystery of why these two vehicles were paired up. So without any further adieu, I flipped a uye' and followed the two.
They pulled into the only building situated up past veterans road on Yucca.
The Animal Shelter.
Why would a big cargo truck and police escort be necessary to transport an unknown subject to the animal shelter at such a late hour?