Jermaine Grant, a British Islamist on trial in Kenya for plotting attacks, had chemicals in his home that could be turned into explosives, investigators testified on Tuesday. Robert John Garrick, a Scotland Yard detective, said they found a stash of battery acid after arresting Grant, who is accused of collaborating with Samantha Lewthwaite, the fugitive widow of one of the London 7/7 bombers. Grant pleaded guilty in December 2011 to being in Kenya illegally and lying about his nationality. He’s currently serving two years for those charges. Security for the trial, which is taking place in Mombasa, Kenya, was ramped up after the mall siege.