article: Police said a man, 27, from Birmingham, who was earlier in custody, and a 39-year-old woman who was on bail have been released with no further action. Four people died and 50 were injured when Khalid Masood drove his car into pedestrians before stabbing a police officer. He was shot dead by police. Fourteen people remain in hospital. PC Keith Palmer was guarding Parliament when he was stabbed by Masood. He was unarmed, but the Metropolitan Police have confirmed that he was wearing a protective vest. A post-mortem examination heard that there was no obvious evidence the vest had been damaged or penetrated, but it had been cut off when emergency first aid was given, the Met said. It added that the coroner had requested that the provisional cause of death was not released at this stage. Eleven people were initially arrested over the incident. In a statement, the Met Police said the 39-year-old woman who was arrested in east London on suspicion of preparation of terrorist acts had been released. Another women, aged 32, who was arrested in Manchester, remains on police bail while police continue their inquiries, it said. The 58-year-old, who is still in custody, was arrested in Birmingham the morning after the attack under the Terrorism Act, meaning officers can hold him for up to two weeks. Police are trying to establish whether Masood acted alone inspired by terrorist propaganda or if others supported him. They are also looking into whether he used the encrypted messaging service WhatsApp to send a message two minutes before he struck. Masood's other victims were Aysha Frade, who was in her 40s and worked at a London sixth-form college, US tourist Kurt Cochran, 54, and retired window cleaner Leslie Rhodes, from south London. Janine Roebuck, a friend of 75-year-old Mr Rhodes, said he was "immensely proud" to have cleaned the windows at Chartwell - the Kent home of Sir Winston Churchill - for "many years". "He was exceptionally fit for a man of his age. I would turn around and he had bounded up the ladder like someone half his age," she told BBC News. "I am filled with huge sorrow that his life has been snatched from him in such an untimely manner." The attack has brought into question security levels at Parliament, prompting a review by police and Parliamentary authorities. Lord Blair, a former Met Police Commissioner who was in charge during the 2005 London bombings, said he was "absolutely certain that there will have to be changes" to the area near the entrance gates where PC Palmer was stabbed. He refused to criticise officers for leaving the gates unguarded immediately after the attack, saying "at that moment they were behaving as human beings". "That incident will have gripped them completely. They will know that the cavalry of the serious armed officers are on their way," he told BBC Radio 4's Today programme. London attack: The victims The path from violent crime to killer The Metropolitan Police said Masood, 52, who had previous criminal convictions but none for terrorism, had
summary: A 58-year-old man is still being held by police over the Westminster attack, as two others are released without charge.