Murderer: Theodore Johnson. Picture: Met Police - Credit: Archant Angela Best's life may have been saved if mental health workers had not missed her relationship with a convicted serial killer because they were “entirely reliant” on him reporting it, a coroner has concluded. Theodore Johnson murdered 51-year-old Angela Best at his his home in Dartmouth Park Hill, Tufnell Park, on December 15 2016 after she ended their 20-year relationship and met another man. He beat and strangled her after she went to his flat to help him with a passport application. Johnson, who had two previous manslaughter convictions for killing his wife in 1981 and another former partner in 1992, spent less than five years in a secure north London mental health hospital before he was let out in October 1997.