US Secret Service boss resigns over Trump shooting failures

US Secret Service director Kim Cheatle has resigned after security failures surrounding an assassination attempt on former President Donald Trump.
"As your director, I take full responsibility for the security lapse," Ms Cheatle said in a resignation letter to agency staff on Tuesday.
She had faced calls from both Democrats and Republicans to step down after a contentious House committee hearing on Monday about the incident.
Lawmakers became increasingly frustrated when she refused to answer questions about the shooting at Trump's campaign rally in Butler, Pennsylvania earlier this month.