The kidnapping happened at the Powell BART station. BART police received a call about the incident shortly after 8 p.m. on Tuesday.
The teenage girl was "forcibly removed" by a male suspect and pulled into a vehicle.
Witness statements and surveillance video confirmed the kidnapping, BART said.
"There may be a potential relationship between the suspect and the victim. This doesn't appear to be a random crime. And the person, the victim was not actually riding BART at the time of the incident. They had arrived in the area in a vehicle," said BART Police Chief Kevin Franklin.
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The teen's parents filed a missing persons report following the incident.
The missing teen was found early Wednesday morning and reunited with her family, BART police said.
A 37-year-old man was arrested by San Francisco police.
This story is developing. Check back for updates.
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