Mark Thielman

When a graffiti artist defaces part of Yosemite National Park, Special Agents Clarence Johnson and Alison Nance expect a straightforward case. But when the suspect falls to her death from Glacier Point—just as another member of her synagogue did years earlier—the investigation takes on a far...

In the Everglades, a senseless murder unearths long-buried secrets. When artist Hezekiah Freeman is found drowned in the shallow waters of Everglades National Park, Special Agent Alison Nance and Clarence Johnson are tasked with uncovering the truth behind his death. What initially seems like a...

A murder in Yellowstone reveals a historical conspiracy, drawing a park ranger into the heart of a centuries-old mystery. When a history professor is fatally shot at the base of Yellowstone Canyon, seasonal park ranger and former homicide detective Clarence Johnson finds himself roped into the...