Conspicuous patrol cars driven by military police officers prowl the streets of Joint Base Myer-Henderson Hall all day, every day.MPs spend their days making sure people notice their presence, and are ready to take any necessary action to protect those who work, live or visit JBM-HH.Sgt. Timothy Ketchum has manned a military police cruiser as a member of the 3d U.S. Infantry Regiment's (The Old Guard) 289th Military Police Company for two and a half years. Riding in between gates on JBM-HH in Arlington, Virginia, and Fort McNair in Washington, D.C., Ketchum's job today as a rover is to assist where he is needed.The 289th served in World War II and Korea before being deactivated in 1955. In 1994, the 289th Police Company became part of The Old Guard.A call comes over the radio: "We have a medical emergency." A 13-year old female is experiencing symptoms of heat stroke inside Arlington National Cemetery. Ketchum takes a right into the Tri-Service parking lot and accelerates to the nearest gate separating the cemetery and JBM-HH.Upon arrival, Ketchum notices paramedics are on the scene. He takes a position near the scene; he needs to be far enough away to avoid interrupting the paramedics. MPs have to respect the privacy of the patient and abide by Health Insurance Portability and Accountability (HIPPA) guidelines.While the cemetery does employ civilian security, MPs respond to assist and secure the area.The most common calls, especially during hot Virginia summer afternoons, are heat-related injuries. On extraordinarily hot days, MPs can respond to half a dozen calls before noon, said Ketchum.Most victims of heat stroke, exhaustion or cramps are children on school trips, he said.MPs also make a record of the report so concerned family members can be advised of the hospital to which their child was taken.The paramedics take the teen away, and Ketchum returns to his patrol.During an eight-hour shift, officers perform tasks like providing over watch of gates and running checks on people trying to come onto the installation. In addition to calls from the cemetery, one of their primary duties is to be a visible presence throughout JBM-HH.Ketchum said most calls on JBM-HH are to the gates."Registration, tags, drivers licenses," Ketchum said. "That's actually where we get most of our drunk driving and drug offenders is from people who made a wrong turn."Ketchum's shift begins early in the morning and often ends with physical training (PT) after their shift is completed in the early afternoon.There are three shifts total: a day shift, an evening shift, and a swing shift.MPs will cycle through the day, swing and night shifts every three months.Becoming a police officer has been an aspiration for Ketchum since high school, he said. His mother insisted he volunteer at the Manassas Battle Field to "give him a taste of manual labor," he said."I foiled her because I liked it," said Ketchum. "The ranger I worked with was a law enforcement ranger, so after that I knew I was going into the Army; that was a foregone conclusion. I walked into the recruiter and said, 'I want to be an MP.'"Enlisting in 1993, Ketchum served five years before leaving the Army and working as a civilian police officer until returning to military service in 2007. He says there are similarities between the two, but also vast differences."They are exactly the same, and then completely different," said Ketchum. "We do the same exact job, only on a smaller scale depending on where you're at. Larger installations; it's like working in a city."