A teenager riding in a car in Hayward was shot and killed by a gunman standing on the center median of a busy street, police said Tuesday.

Samuel Nava III, 17, of Hayward was in a car traveling north on Mission Boulevard at about 6:45 p.m. Monday when it made a U-turn at Industrial Parkway, police Lt. Chris Orrey said. A man standing on the center median opened fire on the car, striking Nava, Orrey said.

The driver continued driving south on Mission and stopped at a shopping center about a mile away. Nava was taken to Eden Medical Center in Castro Valley, where he was pronounced dead.

The gunman was seen running west on Industrial after the shooting, Orrey said. He was described as a white or Latino man in his 20s or 30s, 5 feet 7 to 5 feet 10 inches tall, with a medium build and dark hair. He was wearing long blue jean shorts or blue jean pants and dark shoes.

Nava was the great-great grandson of Pancho Villa and was a varsity baseball player at Hawyard High School, his grandfather, Samuel Nava Sr. of Hayward, said Tuesday.

"He had a lot of charisma," said the elder Nava, 69. "He was the life of the party."

He said he believes the slaying may have resulted from a "stare-off" between his grandson's friends and another group.

Anyone with information is asked to call police through the Crime Stoppers line at (510) 293-7197.