Cpl. Myles Heath, a dog handler with the Provost Marshal

Cpl. Myles Heath, a dog handler with the Provost Marshal Office, Security and Emergency Services Battalion, Marine Corps Base Camp Pendleton, leads Nero, an explosive ordnance detection K9, through an annual certification course on Camp Pendleton, Calif., May 8, 2018. The handler and K9 are required to be recertified each year to ensure the pair is able to perform their duties. In order to pass the recertification, the dog must detect nine explosive components. (U.S. Marine Corps photo by Lance Cpl. Megan Roses)