OAKLAND (KPIX 5) — A woman who was robbed and assaulted on a BART train at the Coliseum station is upset that police didn’t do more to catch the perpetrator.

A Good Samaritan who tried to intervene was also assaulted.

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BART police report they are investigating the incident and are looking through surveillance video to try to identify the suspect.

In an emotional interview, Elaine Sanusi told KPIX 5 she was robbed while texting. Sanusi said she was standing at the door of the train when a man grabbed her phone.

She wrestled him for it, then he assaulted her.

“He just punched me on the right side … of my head,” she said through her tears. “It was my instinct to come after him … So I ran after him and started screaming and yelling ‘Stop him, please help!’”

One man did stop to help. The robber also punched him repeatedly in the head, Sanusi said.

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Sanusi kept chasing the robber down the stairs, but then she twisted her knee and fell to the ground. At that point, the robber ran out of the station.

A police officer quickly arrived to check on her, but she says he didn’t chase the suspect.

“He says, ‘are you okay, everything fine?’ I said yes,” Sanusi recalled. “He goes, ‘Yeah, I just saw him run by … okay, let me just get down the information.’ It was such a process. Something they expect to happen. No sense of urgency, no chase, nothing.”

BART police chief Carlos Rojas told KPIX 5 that his officer didn’t chase the man because he didn’t immediately realize a robbery had taken place. He thought the man running away was probably a fare evader.

Once he stopped to help the victim and realized it was a robbery, the chief said his officer immediately sent out a message on the police radio with a description of the suspect and searched the area, but the robber got away.

Police hope surveillance video will lead them to an arrest.

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“We are taking this situation very seriously,” Rojas said. “We’re going to do our best to identify this individual and take him into custody. He will be facing robbery and assault charges.”