Prosecutors began making the case Tuesday that Terry Nichols deserves to die for his part in the Oklahoma City bombing, putting on the stand a man whose 6-month-old son was so horribly mutilated in the attack that he had to be identified by his fingerprints.

Kevin Gottshall said his son, Kevin Lee Gottshall II, was in the federal building's second-floor day-care center when the bomb went off on April 19, 1995. A photo of the smiling baby was beamed on television monitors to Nichols's jury as Gottshall described the child's death.

A total of 168 people were killed in the bombing, including 19 children.

"Lee was healthy and happy. He was 6 months old and full of potential," Gottshall said. "He had a wonderful smile, and he had six teeth."

But his family never had a birthday party for him.

"All we get to do is go to the cemetery and put stuff on his grave," Gottshall said.

Gottshall was the first prosecution witness to testify in the penalty phase of Nichols's state trial. Nichols was convicted last Wednesday of 161 counts of murder.

In opening statements, prosecutor Sandra Elliott said Nichols deserves to die by lethal injection because he "constitutes a continuing threat to society."

In his opening statement, defense attorney Creekmore Wallace urged jurors to consider all sentencing options in the case. The jury has the choice of giving Nichols life in prison.