A special counsel has been appointed to investigate President Joe Biden after aides found classified documents at his private office and home. The Americast team explains what we know so far, why this spells trouble for the president, and the comparisons between this story and the discovery of hundreds of classified documents at Donald Trump's Mar-a-Lago resort.

President Biden has also been trying to get his immigration policy in order as his administration's approach faces criticism from both Republicans and Democrats. Cecilia Muñoz, a former political adviser to President Obama on immigration, helps the team get into the complexities of America's border politics.

And we investigate the self-styled true crime ‘investigators’ of TikTok, who are gripped by the case of four students murdered in Idaho. We speak to one of them about the dangers of the public getting involved in criminal cases.

Americast is presented by North America editor Sarah Smith, Today host Justin Webb, the BBC's social media and disinformation correspondent Marianna Spring, and North America correspondent Anthony Zurcher.

Email [email protected] with your questions and comments and send us a message or voice note via WhatsApp, to 03301239480. Find out more about our "undercover voters" here: https://www.bbc.co.uk/news/world-us-canada-63530374.

This episode was made by Phil Marzouk and Alix Pickles. The studio director was Michael Regaard. The assistant editor was Simon Watts. The senior news editor was Sam Bonham.