A federal jury sentenced Gary Sampson, 44, to death for the murders of Philip McCloskey, 69, and Jonathan Rizzo, 19.
Sampson pleaded guilty in September to killing McCloskey and Rizzo several days apart in July 2001, after each man picked him up hitchhiking.
Massachusetts last executed someone in 1947 under the state death penalty in effect at the time. The state abolished capital punishment in 1984, but prosecutors pursued the case against Sampson in federal court under a federal law allowing the death penalty when a murder is committed during a carjacking.
It was only the second case in modern times in which federal prosecutors have sought the death penalty in Massachusetts. In the first case, however, jurors decided that nurse Kristen Gilbert, convicted in 2001 of killing four patients, should be sentenced to life.
In 1972, the U.S. Supreme Court ruled that state, and in turn federal, execution procedures were unconstitutional. It wasn't until 1988, during the explosion of crack use, that the federal death penalty was brought back, narrowly applied to cases of murder committed as part of a drug kingpin conspiracy.
In 1994, as part of a national crime bill, the federal death penalty was expanded to about 60 offenses, including fatal carjackings in some cases.
Sampson's lawyer, David Ruhnke, immediately said he will appeal.
"Of course we're disappointed," he said outside the courtroom. "There will be an appeal of the jury decision. The appellate process will run its course."
Relatives of the victims whispered in approval as the sentence was announced and hugged one another before leaving the courtroom.
Because Sampson pleaded guilty, the jury was asked to decide only whether he should be sentenced to death, not whether he killed McCloskey and Rizzo. Jurors did, however, hear the murders described in graphic detail.
Prosecutors portrayed Sampson as a ruthless, calculating killer who preyed on Good Samaritans.
Sampson also admitted killing a third man, Robert "Eli" Whitney, 58, in Meredith, New Hampshire, during the same week, and faces separate state charges in New Hampshire in that case.
He surrendered to Vermont State Police after carjacking another man who jumped out of his car and got away after Sampson pulled out a knife.
Sampson's lawyers focused on a phone call Sampson made to the FBI in Boston the day before he killed his first victim. He said he called the FBI to try to turn himself in because he knew he was on the edge. At the time, he was wanted for five bank robberies in North Carolina.
The call was accidentally disconnected by a clerk, and FBI agents never went to pick up Sampson, as he requested.
Prosecutors told the jury that Sampson had many opportunities to turn himself in, including once, just hours before he killed Rizzo, when he was escorted out of a state park by an environmental police officer.