RELATED: Police search for suspect after 2 stabbed at Berkeley BART station
The transit agency says there's surveillance video showing the victims arguing with the stabber moments before the attack.
A man stabbed another man and a woman on the BART escalator early Tuesday morning.
RELATED: Report shows violent crime on BART increased by 115 percent over last 5 years
The victims were taken to the hospital and treated for their injuries.
BART police are still searching for the suspect.
See more stories and videos related to BART.