UNION CITY -- Police here are asking for the public's help in finding a man suspected of robbing a woman at gunpoint and who tried to sexually assault her earlier this month.

The Sept. 9 attack happened as the woman was walking alone on Almaden Boulevard near Alvarado-Niles Road around 10:30 p.m., police said.

The gun-wielding man approached the woman, forced her to the ground and took her money. As he tried to sexually assault her, a passing motorist startled him and he fled on foot north on Almaden, police said.

The suspect is described as a mixed-race male with a medium build, dark hair, dark eyes and a tattoo on the right side of his neck.

He was last seen wearing a light-colored hoodie with the hood pulled over his head, black pants and black shoes.

Anyone with information or who might have driven through the area at the time is encouraged to contact Det. Jean Luevano at 510 471-1365.