Michael Schoch, Noodle Intern
This is a hard question to answer definitively, but I can point you to other resources that may give a clearer picture.
Abilene High School itself, according to its Noodle Profile, has a Climate rating of 73 out of 100, an Education Quality rating of 85 and an Outcomes rating of 79. Noodle aggregates its data from a wide variety of sources, but combined, these numbers suggest that Abilene H.S has an overall environment that is fairly conducive to learning and academic success. Obviously, that doesn't ensure that there are no gangs or there will never be gangs in the school.
I also found this article from 2009 that acknowledged the presence of gangs in the Abilene community, but emphasized the fact that gang activity was not growing.
I would advise getting in contact with other parents who live in the school district and asking them their honest opinion. Similarly, you should call the school district office at (325) 677-1444.
Lastly, if you are worried about the prevalence of serious gang-related issues, you might try contacting the Abilene Police Department at (325) 673-8331 to see if their records show a high amount of incidents in or around the high school.
Best of luck!