Metro Vancouver Transit Police are asking the public to help identify a man they say committed two violent robberies at SkyTrain stations last month.

The first incident occurred early in the morning on Aug. 18, roughly 15 minutes after midnight. The victim, a 45-year-old man, was on a bus to Marine Drive Canada Line station.

In a video posted by transit police, Sgt. Clint Hampton said, "that man befriended him and when the victim stepped off the bus the man followed."

The suspect asked for a cigarette, and initially walked away when the victim refused to give him one. Hampton said he soon returned, allegedly tackling the victim, and "the suspect held the victim in a headlock until the victim passed out."

When the victim woke up, police said, "the suspect demanded he buy him a drink" at the Canada Line station. While the victim was in the store, the suspect fled on a Canada Line train, taking the victim's phone with him, police said.

The second incident occurred two days later, shortly before midnight on Aug. 20. On this occasion, the suspect approached the victim, a 26-year-old man, near the Stadium-Chinatown Expo Line station.

"The victim was entering stadium skytrain station," said Hampton.

The suspect started a conversation with the victim, who tried to leave, only to be grabbed said police. Then, just like the previous incident, Hampton said the suspect, "held the victim in a headlock until he lost consciousness."

The suspect stole the victim's wallet and later made a $400 purchase from a convenience store using the victim's credit card, police said.

"That’s outrageous," said Jay Lim a SkyTrain passenger. "That's not the type of thing anyone should really be exposed to."

Passengers speaking with CTV News outside the Stadium-Chinatown station said they are cautious, especially at night.

"I don't wear headphones on the train, just in case," said Cassandra Rodrigues.

Luca Succurro said he gets off the train "if anything happens or if I feel like it’s going to involve me at all."

"Metro Vancouver Transit Police is extremely concerned by the level of violence this person is willing to use," said Hampton.

In an effort to identify the suspect, Transit police released both a photo and video of him taken by surveillance cameras at Stadium-Chinatown station prior to the Aug. 20 incident.

Police describe the suspect as a white or Indigenous man in his late 30s. He stands approximately 5'8" to 5'10" tall, with a stocky build and short brown hair. During both incidents, he had a pair of white-framed sunglasses with reflective lenses propped up on his head, according to police.

Police ask anyone who has information about the identity of the suspect or may have witnessed either incident to contact the transit police tip line at 604-516-7419 and refer to file 2019-15236. Tips can also be provided via text message at 87-77-77.