COLUMBIA, S.C. — Nearly 10 months after her 18-month-old son was last seen, a South Carolina woman was convicted Friday of unlawful conduct for refusing to tell authorities where he might be, just insisting that he is safe.

Zinah Jennings, 23, showed no emotion as the verdict was read. The jury of eight women and four men deliberated for about 2½ hours before issuing its decision, and a judge sentenced Jennings to the maximum of 10 years in prison. Jennings has been held without bail since her arrest.

The last time Jennings’s son, Amir, was seen was November, when a security video at a bank recorded them both.

Police say Jennings repeatedly told them false tales that led them to search places from Atlanta to Charlotte, N.C.

Jennings, who did not testify in her defense, has said she left the boy somewhere safe but would not give details when questioned by police. Prosecutors played a lengthy police interview in which Jennings cried as she said her son was safe but that she could not prove to detectives that the boy was alive.

Investigators have found Amir’s blood on baby blankets retrieved from Jennings’s car but no other trace of him.

Some of the dozens of prosecution witnesses testified during the two-week trial that Jennings — who gave birth to a second child last week — said she was overwhelmed by the stresses of parenting an active, energetic boy and needed a break. One friend said Jennings told her she pondered selling or giving away Amir and even mentioned throwing the boy out the window of a moving car.

Other prosecution witnesses testified that they saw Jennings kick Amir when he misbehaved or squeeze his hand when he wouldn’t say ‘‘mama.’’ Employees at the bank where the video came from testified that Amir was often not in a car seat when his mother pulled up at a drive-through window.

Jennings’s mother said she doesn’t believe her daughter would have ever harmed Amir.