Despite video evidence that captured the brutal attack, the San Francisco Police Department has been unable to track down the people responsible for the February stabbing of a British tourist that led to his death. Will these composite sketches or a $5000 reward lead police to the killers?

You likely know the story by now: 44-year-old Paul Tam, an IT expert from Manchester England, was visiting SF in pursuit of "new career opportunities," when a man and woman attempted to mug him at around 8:30 p.m. on Thursday February 18 as he walked on Post Street, between Franklin and Gough Streets. He resisted the theft of his green messenger bag, which contained his passport, cash, credit cards, and his cell phone, and was stabbed in the head by his mugger. He succumbed to his injuries on March 24.

The mugging and attack was captured on a nearby video camera. It is graphic.

The male and female suspects in the attack grabbed Tam's bag and fled. They have not been seen since.

Using the video, an SFPD artist created the composite sketches of the man and woman responsible for the mugging and attack that you see above. The SFPD also provides these descriptions:

Black adult male approximately 5’10” with a heavy build last seen wearing a dark hoodie and blue jeans

Black/mixed race adult female approximately 5’4”, small build with dreadlocks or braids.

Of the male suspect, SFPD spokesperson Officer Carlos Manfredi told ABC 7 that "He took a bag of items and killed someone for it."

"If he could do it to this person, he could do it to someone else."

According to Bay City News, the San Francisco Police Officers Association is also offering a $5,000 reward for information leading to the arrest of the suspects. That's additional incentive for those who know anything about the attack to contact Sergeants Chris Canning, Scott Warnke, Anthony Ravano or Alan Levy at the Homicide Detail during business hours at (415) 553-1145, or anytime via the Anonymous Tip Line at (415) 575-4444 you can also Text A Tip to TIP411 and begin the message with SFPD.

Previously: British Man Stabbed On Cathedral Hill Last Month Dies; Police Release Video Of Attack