By Scott Malone
BOSTON (Reuters) - Jurors should spare the life of a Massachusetts drifter who killed three men in separate 2001 attacks because a series of brain injuries suffered as young as age 5 hurt his ability to control his emotions or impulses, his attorney said on Wednesday.
Prosecutors challenged that claim, citing the detailed planning that Gary Lee Sampson went through before and during his killing spree, including buying rope to more securely tie his victims and switching from stabbing them to strangling them when he tired of getting victims' blood on himself.
Sampson, 57, could be the second person sentenced to death by a federal jury in Massachusetts in two years, a rarity in a state whose laws do not allow the death penalty.
He pleaded guilty to killing two men in Massachusetts after hailing them as a hitchhiker and taking them to secluded wooded areas where he tied them up before stabbing them to death. He later strangled a third man in New Hampshire.
Sampson suffered a series of injuries, including from a fall of 10 feet (3 meters) when he was about 5 years old, that injured his brain and prevents him from fully controlling his actions or emotions, defense attorney Michael Burt said.
"It's helpful to look at those injuries and ask not whether it excuses, not whether it justifies, his crimes but does it help explain how he had been doing all these horrific crimes and running amok?" said Burt, as he presented the jury with some 115 mitigating factors that he said justify sparing Sampson’s life.
Assistant U.S. Attorney Zachary Hafer dismissed the significance of the injuries.
"This is a convenient brain injury, this is a strategic brain injury, this is an imaginary brain injury," Hafer said.
He showed the jury the pocketknife Sampson used in the killings, as well as photos of his victims before and after their slayings.
Sampson was sentenced to death in 2004, but a judge in 2011 overturned that sentence after learning that one of the jurors had lied about having been a victim of domestic violence.
Sampson's victims were Philip McCloskey, 69, Jonathan Rizzo, 19, and Robert Whitney, 58.
In a police tape played to the jury, Sampson told his interrogator that he changed his murder method for his last victim, the caretaker of a home on Lake Winnipesaukee in New Hampshire, because "I didn't want no more blood on me."
(Editing by Tom Brown and Dan Grebler)