Shades of Mercy

"Porter Beck is the sheriff in the high desert of Nevada, doing the same lawman's job his father once did now that he's returned home after decades away. ... [His] twelve-person department [covers] a large area that is usually very quiet, but not of late. One childhood friend is the latest to succumb to a new wave of particularly strong illegal opioids, another childhood friend--now an enormously successful rancher--is targeted by a military drone, hacked and commandeered by an unknown source. The hacker is apparently local--local enough to call out Beck by name--and that means they are Beck's problem. Beck's investigation leads him to Mercy Vaughn, the one known hacker in the area. The problem is that she's a teenager, locked up with no computer access at the secure juvenile detention center"--