<p>BOSTON -- Two young children were found slain on Tuesday and later their mother was fatally shot by police after threatening officers with a knife, according to a police spokeswoman.</p>
<p>Police responding to a domestic disturbance at the home in Boston's Dorchester neighborhood found the unidentified boy and girl -- their throats slashed -- in the basement at 3:50 p.m., police spokeswoman Mariellen Burns said in a brief statement.</p>