Montgomery County detectives are seeking a potentially key witness who may have boarded a transit bus just after a 24-year-old man was fatally shot late last year in the White Oak area of Silver Spring, authorities said Friday.

About 6:39 a.m., Dec. 27, police received several calls of gunshot sounds in the 11400 block of Stewart Lane, which is about five blocks east of the intersection of Columbia Pike and New Hampshire Avenue.

After arriving, officers found Franklin Ikechukwu Amobi, 24, of the nearby 11200 block of Columbia Pike, suffering from gunshot wounds. Police found evidence a gun had been fired at the scene.

Detectives later learned there may have been a witness, but so far they’ve only got a vague description of her: An older, Hispanic woman. Detectives believe she boarded a Metrobus traveling the Z8 Fairland Line shortly after the shooting. She likely used a bus stop at 11412 Stewart Lane.

“Police are urging this witness to come forward to provide additional information,” authorities said in a news release.

A reward of up $10,000 is available for help solving the case, with a number to call of 1-866-411-TIPS (8477). Those with information also can call homicide detectives at 240-773-5070.

Read more: The Post’s crime coverage