After Prof Crane had given his evidence, she asked the pathologist why her son Nevin appeared to have "succumb to the gas more quickly".

BBC: Noel (L), Nevin (centre) and Graham Spence (R)

She ignored warnings from a private security guard, her son said, and amateur video shows her falling as he appeared to drag her from the train.

BBC: US mayor 'sorry' elderly woman removed from train

Four years slipped by, and one day, Mercedes Funes appeared at the clinic with her son in tow.

NEWYORKER: Sin Dolor

"Only his mother appeared before the judge to say that she had lost control of her son after he left the house at about age 11, " the prosecutor, said.

CNN: 13-year-old assassin murdered in Mexico

Seventy-eight-year-old Betty Douglas, who divides her time between Wisconsin and South Florida, appeared briefly on stage with Mr. Ryan but didn't speak at her son's campaign rally.

WSJ: Paul Ryan Makes Case for Medicare Overhaul