Law enforcement officials continue to examine the cause of two fatal motor vehicle accidents last week in Southern Maryland, as well as the unexplained death of a man found on the side of a road in Malcolm that police believe was likely a hit-and-run incident.

Charles County sheriff's officers have been canvassing a neighborhood in Malcolm after discovering the body of an Upper Marlboro man on Malcolm Road near the Prince George's County border in northeast Charles, police said.

John Kenneth Pinkney, 40, was found lying on the side of the road in the 3300 block of Malcolm Road about 10:15 p.m. Tuesday, police said. Pinkney had been visiting a friend in the area and may have been walking to a relative's home, police said. His body had head injuries consistent with being struck by a vehicle, police said late last week, although they were still awaiting the results of an autopsy.

Meanwhile, in Calvert County, the sheriff's office is trying to determine what caused an accident Tuesday afternoon that killed a 14-year-old Calvert High School student.

Julie Anne Cox, of Huntingtown, was riding in a car driven by a 17-year-old male friend about 5 p.m. Tuesday when it struck a parked flatbed trailer in the 5000 block of Hillside Road in St. Leonard. Cox died at the scene. The driver was taken to Calvert Memorial Hospital, where he was treated and released.

Sheriff's Sgt. William Soper said that police believe the 17-year-old driver, whose name was not released, may have been blinded temporarily by the sun as he navigated narrow streets in the residential neighborhood. Construction workers had used the trailer to haul a front-end loader being used at a home in the area, Soper said.

"We're looking into the possibility that as the result of the sun glare, he failed to negotiate around the trailer," Soper said. The state's attorney's office was reviewing the case to determine whether charges would be filed.

In another accident early on Wednesday, a motorcyclist struck and killed a pedestrian as he tried to cross Mattawoman Beantown Road in Waldorf, Maryland State Police said.

Mark Steven Holl, 40, of Waldorf, was crossing the road about 3:13 a.m. when he was struck by the motorcycle driven by Christopher M. Kemp, 19, of Mechanicsville.

Holl was pronounced dead at the scene. Kemp, who was severely injured in the crash, was flown to Prince George's Hospital Center on a state police helicopter. At week's end, he remained in serious condition, according to hospital officials.