One notable case involved Cui Yingjie, a fruit vendor from north China's Hebei province who killed a chengguan officer in Beijing in 2006 after having his fruit cart violently confiscated.
"I heard the vagrants cry 'thieves' when the vehicles left," the bus driver said.
Some of the victims voiced their grievances to Yu Jianrong, a Beijing-based social researcher who launched an online campaign last month calling on citizens to donate quilts and winter clothing to help the homeless survive the bitter winter.
Beijing is experiencing its coldest winter in decades, with temperatures slumping to minus 15 degrees Celsius. The city's homeless are still bedding down in the open air, however, seeking shelter only when it snows.
"An elderly man called me on Sunday and asked for help. He gave his name as Dong Jiangai," said Yu. "He said he was freezing and asked me to save him."
Dong, 70, said his bedding was taken by the chengguan, adding that he was warned by the officers to leave the area as well.
Spring Festival draws near, immigrant workers have begun to go home, leading a travel peak at the railway station.