If a video camera had been mounted inside Yellow Taxi No. 150 on Wednesday night, would it have prevented the shooting death of its driver, William R. Harper?

Yemane Mebrahtu, president of the Minneapolis Taxicab Drivers and Owners Association, thinks so, and he said it's time for the industry to adopt camera requirements for all taxis. "We need to have a statewide law," Mebrahtu said. "With the technology we have, it's not that expensive."

A police investigation continued Friday into Harper's death. The 56-year-old Roseville man was shot in the back at 10 p.m. Wednesday as he sat in his cab on a north Minneapolis street.

It was after two back-to-back cabdriver killings in 2003 that the city adopted safety rules for all cabs, saying they must at least have a security shield, a GPS system or a digital still camera that takes pictures every five seconds.

While a few companies have installed cameras, most vehicles have the GPS system, which, when triggered, alerts the taxi company's dispatcher to the vehicle's location and turns on a two-way radio. "They will identify where the car is," said Mebrahtu. "That has nothing to do with the safety of the driver."

Late Friday afternoon, taxi drivers and others gathered for a brief vigil at the spot where Harper was fatally shot in the 400 block of 23rd Avenue N.

Taxi drivers have one of the most dangerous jobs in the country, with only police officers and security guards facing a higher likelihood of being assaulted while working, according to the Occupational Safety and Health Administration as well as the National Institute for Occupational Safety and Health. Drivers are 60 times more likely to be killed on the job than other workers, according to a 2000 study. Some 45 taxi, bus and limo drivers were slain nationwide in 2010, according to the latest federal statistics.

A few places in the United States require cameras, including San Francisco, which hosted a convention last year for the Taxicab, Limousine & Paratransit Association, an association for the private passenger transportation industry.

Steve Pint, president of Taxi Services Inc., Harper's employer, said he was impressed by the camera systems he saw at the convention.

"We're very much in favor of it," he said. His company had cameras in vehicles about a decade ago, but the technology wasn't as reliable as it is today, he said.

Pint said some drivers might resist the added surveillance, even as a safety measure. "We were going to do a test with a driver and he was worried about it, saying, 'Does it have to be on when I'm driving around with my family?'"

A Portland, Ore., company that sells in-car video surveillance systems said most of them cost between $500 and $1,000. Color, high-definition video with audio is possible, said David Raske, a spokesman for Videosurveillance.com. "It's important that the camera is more substantial or vandal proof," he said.

Some of the video cameras they recommend attach to the vehicle's ceiling toward the front of the cabin. A wide-angle lens captures everything in the back seat, and even some of the driver's face. The images are stored on removable cards placed in a separate device stored in the vehicle's trunk, he said.

Mike Belete, a co-owner of Edina Taxi, said he would like to see more cameras installed as well. Some taxi drivers just post a sticker saying the vehicle is equipped with a camera, even if it isn't.

Belete said he's also seen systems that snap a photograph of each customer a few seconds after they enter the cab, while the vehicle's dome light is still on. "They are actually much cheaper" than a video camera system, he said.

Harper's death has hit the taxi community hard, Belete said. "I'm very, very sad about this whole situation," he said. "It's very heartbreaking."

Matt McKinney • 612-217-1747