What do we know about US Vice President Kamala Harris, who is thought most likely to win the Democratic Party nomination after the withdrawal of Joe Biden? What are her strengths - what are her weaknesses - and does she have a path to victory? Also in the programme: the battles between the Mexican state and the drug cartels claim yet another victim - Mexico City's police intelligence chief; and a BBC investigation tracks down one of South Africa's most notorious serial killers – Louis van Schoor – who shot dead dozens of black men and boys in the late eighties, but was controversially released from prison, and now says police colluded in his crimes.

(IMAGE: U.S. Vice President Kamala Harris looks on during an event with the women and men's National Collegiate Athletic Association (NCAA) Champion teams in her first public appearance since President Joe Biden dropped out of the 2024 race, on the South Lawn of the White House, Washington, U.S., July 22, 2024 / CREDIT: Reuters/Nathan Howard)