A D.C. police officer whose daughter was robbed of $17,000 belonging to her drug-dealing boyfriend is facing an internal investigation for failing to report the crime and the boyfriend's apparent threat to retaliate.

It was not until the suspected robber was gunned down the next day that Sgt. Fred E. Johnson contacted his colleagues in the homicide unit, where he was a supervisor, and told them that he had information about the April 1, 2003, slaying in Northwest Washington.

Prosecutors said that the boyfriend, Harry Wheeler of D Street SE, a convicted drug dealer, arranged the killing of 22-year-old Michael Taylor a day after two gunmen broke into the R Street NW home where Johnson's daughter, Brittainy Johnson, and other relatives were living. Wheeler, now 21, was arrested about a month later.

While the prosecution of Wheeler was pending, Johnson continued to supervise homicide cases. Then, a day after Wheeler was convicted of first-degree murder and other charges in February, police launched an internal investigation into Johnson's conduct, Wheeler's defense attorney said yesterday.

Defense attorney Douglas J. Wood cited the probe in asking that Wheeler's sentencing yesterday be postponed, saying he had learned of the investigation from prosecutors only Wednesday. Wood said the timing of the investigation raised new questions about the credibility of Johnson, who was a prosecution witness in Wheeler's trial in D.C. Superior Court.

"I submit there was a conscious decision not to have an investigation ongoing while he was a critical witness," Wood told Judge Judith E. Retchin.

The U.S. attorney's office said yesterday that prosecutors did not do anything to encourage police to delay an investigation of Johnson.

During the trial, Johnson testified that his daughter called him soon after the robbery. He said that he urged her to report the crime immediately but that she did not want to go to police. Fred Johnson later told investigators that in the hours after the robbery, Wheeler had said, "I'm going to have to go to jail behind this one." He did not report the robbery or that statement until after Taylor's death.

Retchin rejected the defense request to delay Wheeler's sentencing. The judge said Johnson's conduct, while not that of a "model police officer," was a matter separate from the sentencing.

Looking to the judge and to the spectators, Wheeler apologized to his family and expressed his condolences to Taylor's family but continued to assert his innocence.

"I had nothing to do with his death," Wheeler said. "I ain't going to say I was saint, but I'm not a killer."

Retchin dismissed his denials, declaring, "You were your own judge, jury and executioner." Saying Wheeler would not be out until he was a senior citizen, she sentenced him to 45 years in prison.

For Michael Taylor's parents, Amber and Darryl Barbour, it was a moment of justice. But they remain angry with Johnson. If he had come forward sooner, they said, their son might still be alive.

"He really needs to be held accountable for his actions," Amber Barbour said.

Sgt. Joe Gentile, a police spokesman, said Johnson had been transferred to a desk job with no public contact. But, citing department policy, Gentile said he could neither confirm nor deny that Johnson was the subject of an internal affairs investigation.

At the courthouse yesterday on an unrelated case, Johnson declined to comment.