A paroled bank robber from Philadelphia was convicted yesterday in D.C. Superior Court of killing a rookie transit police officer almost three years ago in a confrontation over evading the Metro fare.

In a courtroom packed with police officers, jurors said they found Walter O. Johnson, 36, guilty of all seven charges against him in the killing of Officer Marlon F. Morales, including the top charge of murder of a law enforcement officer.

Johnson, whose lawyers argued that he was not in the District on the night of the shooting, appeared to raise his eyebrows a bit as the jury returned its verdict, his face locked in the frown that was his usual expression through the trial.

Delivered late yesterday afternoon, the verdict was the culmination of three days of deliberations, following a trial that spanned nearly two months.

Afterward, Morales's widow said that she was relieved that the trial was finally over but that her ordeal continues.

"Unfortunately, the outcome doesn't change the fact my husband is still gone, and my children's father is gone," Jennifer Morales said as she stood with Jeremy, 13; Joshua, 11; and Megan, 3, who was born a few weeks before her father was killed.

Morales struggled to hold back tears as she read a statement to reporters outside the courthouse. Megan looked up, seemingly puzzled by it all.

"She was just 19 days old the last time her daddy gave her a kiss on his way to work," Morales said of her daughter. "She just turned 3, and she'll never have her dad with her for a birthday party."

Shot in the head June 10, 2001, in the U Street/Cardozo Metro station, Morales died three days later. An immigrant from Guatemala, he was 32 and had been a police officer for less than a year. He was the second Metro transit officer killed in the line of duty.

Johnson, who served 10 years in federal prison for armed bank robbery, was paroled four weeks before his deadly encounter with Morales. During his time in federal prison, he beat up Mafia boss John Gotti, who was a fellow inmate for a time, according to court documents.

When Johnson is sentenced July 30 by Judge Ann O'Regan Keary, he could be imprisoned for the rest of his life without the possibility of release.

With no eyewitnesses to the shooting, the prosecutors, Assistant U.S. Attorneys June M. Jeffries and David Gorman, had to marshal a wealth of circumstantial evidence challenging Johnson's supposed alibi and tying him to the killing of the officer.

Johnson was identified by the station manager as the fare evader stopped by Morales moments before the shooting. When police pulled him over a few days later in Philadelphia on an unrelated matter, Johnson had Morales's gun, which had been stolen after the officer was shot.

Working with investigators in Philadelphia, detectives from the District tied the gun used to kill Morales to a shooting days earlier in Philadelphia. That weapon was not recovered, but the victim in the shooting identified Johnson as the assailant.

For a man on parole -- and facing the prospect of being sent back to prison if found carrying a gun used in a crime -- being stopped for fare beating was a powerful motive for murder, prosecutors said.

Arguing that this was a case of mistaken identity, Johnson's attorneys, Renee P. Raymond and Yvonne Williams of the D.C. Public Defender Service, challenged many of the witnesses' accounts and many of the prosecution's assertions.

Jurors rejected the defense's contention that Johnson was back in Philadelphia the night of the shooting and the argument that he just happened to buy Morales's gun from someone in Philadelphia.

Detective Gary A. Padgett, the lead Metro transit investigator in the killing, has spent the past three years helping prosecutors prepare for the trial and helping the slain officer's family cope with their loss.

"It's been a long three years," he said, reluctantly stepping to the microphones outside the courthouse.

"I felt a tremendous relief for the family because what they've been through has just been tremendous," Padgett said. "I can't imagine losing my spouse."

Flanked by sons Jeremy, left, and Joshua, with daughter Megan in front, Jennifer Morales, widow of Officer Marlon F. Morales, speaks with reporters.