President Biden says there is no place for "political violence in America". His warning follows an attack on Paul Pelosi, the husband of US House of Representatives Speaker Nancy Pelosi, last week. Within hours of that attack a series of unsubstantiated claims began circulating on social media contradicting official accounts of what had happened. Those misleading claims then went viral after being amplified by new Twitter chief Elon Musk.

The Americast team look at how the attack has led to the sharing disinformation on social media and Justin and Sarah speak to author Josh Zeitz about the history of political violence in the US.

Donald Trump Jr. tweets about our 'undercover voters' and Marianna Spring, the BBC's Social Media and Disinformation correspondent responds. And Anthony returns from Virginia to look at Biden’s record ahead of the midterms.

Americast is presented by North America editor Sarah Smith, Today presenter Justin Webb, North America correspondent Anthony Zurcher and Marianna Spring.

Find out more about our ‘undercover voters’ here: https://www.bbc.co.uk/news/world-us-canada-62742687

Email Americast@bbc.co.uk with your questions and comments. You can also send us a message or voice note via WhatsApp, to +443301239480

This episode is made by Phil Marzouk and Alix Pickles. The studio director is Michael Regaard. The assistant editor is Louisa Lewis. The senior news editor is Jonathan Aspinwall.