Defense attorneys suggested that Nelson had serious family issues that led to setting his mother's bed on fire at age 3 and his other intentional attempts at burning down his house at age 6.
Kelleher said she did not know about those incidents, apparently documented in reports from Oklahoma, where Nelson and his family lived before moving to Texas.
Several Tarrant County jail guards testified that about a year ago, Nelson broke a jail phone when he became upset after talking to someone. Nelson then cursed, threatened and bumped one guard, and it took three to restrain him, according to testimony.
Nelson has been charged with assaulting another jailer in October 2011, which happened about a month later. Nelson also is a suspect in another inmate's death.
Jail guards also testified that during his time in jail before the trial, Nelson broke a light in his cell and destroyed sprinkler heads, and that guards found a shank and narcotics in his cell.
Testimony by prosecution and then defense witnesses is expected to continue the rest of the week, after which jurors will decide Nelson's sentence.