do a deed of merit

1. 'Do a good deed of merit in sb's behalf'is ofter applied in breaking drug crime, smuggling crime, criminal syndicate, career crime or arresting suspects.
    “代为立功”常常运用于毒品犯罪、走私犯罪、有组织犯罪、职务犯罪案件的破获或者犯罪嫌疑人的抓获。