A federal jury convicted a Newport News, Va., man of murder yesterday for blowing up his pregnant ex-girlfriend to avoid paying child support.

The jurors now must decide whether Coleman Leake Johnson Jr., 29, should be executed for planting the 1997 bomb that killed Tammy Lynn Baker, 24. Testimony in the sentencing phase of the trial begins in Charlottesville this morning. Johnson could become the first white Virginia defendant to receive the federal death penalty since capital punishment was reinstated in 1993.

Baker was killed Dec. 3, 1997, when she picked up a trash can lid and set off a pipe bomb left outside her apartment in the small town of Louisa, Va. The blast scattered debris more than 600 feet and was heard 10 miles away. The blast killed Baker and her 8-month-old fetus instantly.

No physical evidence linked Johnson, who has no criminal record, to the crime.

But prosecutors called acquaintances of Johnson, known as Mike, to testify that he knew how to build the type of pipe bomb used to kill Baker, and had gotten angry with Baker and other women about the issue of child support. An ex-girlfriend also testified that Johnson had told her he was going to Louisa the night before Baker died.

"We're very, very happy. It was a very tough circumstantial case," said Assistant U.S. Attorney Tom Bondurant. "We're extremely happy that it all came together."

Johnson's attorneys tried to tie the attack to two other bombs that went off in Louisa and nearby Mineral four months after Baker's death. Johnson had an alibi for those explosions.

Johnson's mother, Dianne, testified that her son was home the night before the bombing and could not have sneaked past where she was sleeping on the couch.

Frederick T. Heblich Jr., Johnson's lead defense attorney, said, "We're disappointed in the jury's verdict, but from what we can [tell] they deliberated carefully and based their decision on the facts, not emotion.

"We think we got a fair hearing, and we hope they will use the same criteria for the penalty phase," he said.

One of Baker's relatives said the family plans to wait until after the sentencing to talk to the media.

Bondurant said he intends to call family members to explain the impact of Baker's death. Other factors that may influence the jury could include the risk the bomb posed to others and the pecuniary motive for the crime.

But Heblich said he will emphasize his client's clean record and steady employment history, and psychological evidence that could help the jury understand Johnson's family background.

Baker, who grew up in Louisa, was working two jobs at the time of her death. She met Johnson the previous spring, while he was working for a contractor doing repairs at the nearby Lake Anna nuclear power plant. He stayed in her apartment for about two weeks of his two-month stint in the area, and had gone home to Newport News when she called to tell him that she was pregnant.

Baker's mother, Barbara, told the jury that she overheard conversations between her daughter and Johnson in which they fought about child support.

But the defense argued that the bomb could have been left for Baker's former housemate or connected to the two other blasts, which wounded three people. The three explosions shook Louisa's 1,400 residents, and many in the area were convinced that a serial bomber was at work. No arrests have been made in the other bombings.

But investigators homed in on Johnson as a suspect in Baker's death and concluded that the other two pipe bombs were not related.

The jury deliberated about six hours over two days before finding Johnson guilty.

"We're very pleased with the outcome," said Special Agent Harold Scott Jr., spokesman for the Washington field division of the Bureau of Alcohol, Tobacco and Firearms, which investigated the case with the Virginia State Police and Louisa authorities. "It was a cowardly attack and we're glad justice has been done."

Coleman Leake Johnson Jr. could be the first white defendant in Virginia to get the federal death penalty since it was restored in 1993.