A Boston police captain based in Mattapan was the highest-earning city worker last year, according to payroll data released on Friday. The captain, Haseeb Hosein, earned a total of $366,232 in 2017. A significant amount of that pay - $106,980 in total - came from detail work, while another $62,696.50 came from overtime pay. Hosein wasn't the only city employee who earned more than $300,000. Ten other city workers, all employed by the police department, earned $300,000 or more.