Boston was riveted last week by a paralyzed little girl, Kai Leigh Harriott, who publicly forgave the man who fired the shot that put her in a wheelchair. Anthony Warren pleaded guilty and will serve 13 to 15 years in prison.

The day before, however, the Boston Police Department (BPD) had been unable to find justice for another child in the line of fire. After Suffolk County presented a purely circumstantial case — in which at least one witness described the shooter as ten inches shorter than the defendant — a jury took well less than two hours to acquit Kevin Johnson of the 2003 murder of 15-year-old Steven Jackson.

Johnson’s family maintains that he is innocent of the shooting, which took place in broad daylight in the middle of a Roxbury street. Regardless, there is no justice for Jackson’s family, members of which wailed and fumed after the verdict was read.

Unfortunately, this is hardly an anomaly. Since 2002, the BPD has investigated nine murders of victims under age 16, without getting one conviction to date. (This does not include incidents of domestic child abuse, for which the DA’s office has had considerable success.) The BPD has made arrests in all but one case — far better than its overall homicide-arrest rate of less than 50 percent. But not one person has been convicted at trial or pleaded guilty to any of the nine murders.

James Bush was found not guilty last year of the 2002 murder of three-year-old Malik Andrade-Percival. Also last year, Marquis Nelson was acquitted of killing 10-year-old Trina Persad. A mistrial was declared for Nelson’s codefendant, Joseph Cousin, who should go to trial again later this year. Carey Reid, arrested for the death of 14-year-old Eon Hoskins, was murdered while out on bail earlier this year.

Next up is Kentell Weaver, on trial as of this writing for the 2003 murder of 15-year-old Germaine Rucker. Defendants in three more cases are moving closer to trial. As they do, let’s hope for more-satisfying endings.