San Francisco police released sketches on Monday of a pair of suspects wanted in connection with the killing of a British tourist who was stabbed in the head during a robbery in February.

Paul Tam, 48, was walking with his niece on Post Street, between Franklin and Gough streets, when two thieves attacked them.

Surveillance video recovered by investigators shows what police describe as a “brutal” slaying. Tam and one suspect faced off around 8:30 p.m. in an oncoming lane of traffic. Tam tried to run away, but the suspect charged at him with what appears to be a knife in one hand.

A car rolled through the struggle and stopped for a moment as the suspect, who wore a large dark hoodie and baggy blue jeans, knocked Tam to the ground and stabbed him.

Tam died March 24, about a month after the robbery.

Sketches of the homicide suspects depict a black man with a hood draped over his head and a black or mixed-race woman with dreadlocks or braids. The woman is not visible in the surveillance footage.

The male suspect is described as about 5 feet 10 inches tall with a heavy build. He is believed to be between 30 and 40 years old.

The 5-foot 4-inch woman is said to have a small build and be in her late 20s. No description of her clothing is available.

Tam’s death marked the ninth homicide of the year in The City.

The San Francisco Police Officers Association is offering a $5,000 reward for information leading to the arrest of the suspects.

Homicide investigators are seeking information from anyone who might know the suspects or who observed suspicious activity in the area when the crime happened on Feb. 18.

Below is the graphic surveillance footage from the night of the stabbing:

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