The late Brooklyn District Attorney Ken Thompson, who also had a decade-long career as a successful private attorney, left his family $750,000 in a will he signed just 12 days before he died of cancer last month.

Thompson succumbed to colorectal cancer at age 50, three years after becoming the borough’s first African-American DA and only five days after announcing he would take a leave of absence for health reasons.

Thompson signed his will on Sept. 27, leaving his estate to his wife Lu-Shawn and his two children in a series of trusts that amount to $750,000, according to documents filed in Brooklyn Surrogate’s Court Thursday.

Before he became DA, Thompson ran a private practice.

Thompson revealed on financial-disclosure forms that he made $500,000 in 2012, according to a story on DNAinfo.com.