ially, Chaidez testified. He said Sierra acknowledged selling street narcotics while looking for legal employment and hoped improving his financial situation would help bring his children back. Under questioning, Chaidez said Sierra did not tell him he was unable to keep a job or that a brain injury prevented him from holding one. The testimony also focused on Sierra's demeanor while discussing the victims. Chaidez testified that Sierra remained calm when talking about his dead wife and did not become emotional when discussing his dead stepchildren. At another point, the lead prosecutor asked whether Sierra had described himself as having a  broke brain  or  broken brain.  Chaidez testified that he had not. The testimony adds to the evidence prosecutors are presenting as they seek to persuade jurors that the killings were especially  heinous, atrocious and cruel,  one of the factors relevant to the death penalty. Prosecutors also have argued the murders were committed in a  cold and calculated manner. 



Sierra, now 42, has pleaded guilty to three counts of murder and three counts of kidnapping in the killings. Prosecutors say Sierra suffocated Machado and her daughters with yellow plastic shopping bags. Sierra also has admitted to cutting Machado's clothing with a knife, according to prosecutors. Prosecutors have alleged that he sexually assaulted Machado and Julia after their deaths. The penalty phase follows Sierra's guilty pleas and will determine whether he receives a life sentence or the death penalty. The jury will hear evidence from both sides before making a recommendation on his sentence. The new testimony came as the defense sought to give jurors a different context for Sierra's behavior and cognitive functioning. Defense attorneys are asking jurors to consider the effects of a severe childhood brain injury on their client. Defense attorneys, who are seeking a life sentence, have described Sierra's mother as an immigrant from Cuba and said Sierra suffered a severe brain injury after being hit by a car at age 12, causing lasting changes to his personality and executive functioning.