Among those freed were three men accused of pumping seven bullets into the head of 19-year-old Leon Elem in 1997 as he walked through their neighborhood on a day off from his job at McDonald's. One of the defendants gave a full confession, but it was later quashed because detectives interrogated him without his attorney present. Lacking any other evidence, prosecutors agreed to plea deals that set them free.
Further analysis shows that at least 83 defendants charged with homicide and later released were subsequently rearrested for new crimes - including 24 indicted in fresh murders or attempted murders.
Over the past five years, records show, this group has been charged 683 times in such crimes as rape, carjacking, firebombing, kidnapping, armed robbery and a staggering 123 murders. A third of them were teen-agers when they were first accused of taking a life.
Among them is Juwarren A. Bowers.
Just 16 years old when he was acquitted in the 1997 robbery-murder of Korean grocer Chi Sup Kim, Bowers shot his aunt's fiance in the face three months later. Charged with attempted murder, he received a five-year plea deal and is scheduled to be released in time for his 21st birthday.
"This will come as a shock to most people in Baltimore, because the conventional wisdom is that a lot more is being done to get these guys off the street than is really going on," says Judge John N. Prevas, who regularly presides over murder cases in the city's Circuit Court. "But the margins for error are so thin in this business, it doesn't take much to push things over the edge ... and the [Police Department] has been at a low ebb for quite some time now.
"As surprising as it sounds to the average citizen, to the professionals in the system it won't come as a surprise at all."
Geoffrey P. Alpert, a criminology professor at the University of South Carolina who has studied police trends for more than a decade, called the data "a red alert for major city police chiefs across the country."
"For many years now, we've suspected something like this was going on," he said. "This is really scary stuff, and there's good reason to believe it's probably happening in a lot of major cities right now, or will be soon."
In Baltimore, plunging clearance rates - the number of murders in which police arrest a suspect - coupled with a 44 percent failure rate in court have repeatedly left killers on the street. In large measure, records suggest, it is these repeat offenders who have ensured Baltimore's place on the list of America's five deadliest cities for a decade.
How could it be that serial felons, whose names are well known in law enforcement circles, continue to escape punishment?
The reasons are complex and intertwined.
Among the biggest factors were a steep decline in the quality of basic police work in Baltimore; political infighting between the mayor and state's attorney's office; an increasing reluctance among witnesses to come forward; and deepening cynicism among some jurors about the credibility of police on the witness stand.
First and most important among these was an unprecedented surge in retirements in the Baltimore Police Department that sapped the force of experience and threw the Criminal Investigations Bureau into disarray.
The sudden increase in the number of officers with less than five years' experience in their jobs - currently a third of the 3,200-member department and more than half of the homicide unit - sparked a rise in everything from squad car accidents to evidence mishandling at crime scenes.
As the quality of investigations declined, court records show, prosecutors demonstrated an increasing willingness to drop charges against defendants for lack of sufficient evidence.
The reason: Detectives in Baltimore have sole authority to decide how much evidence is enough to charge someone with murder - and prosecutors do not have the power to order them to investigate further to strengthen the case for trial.
Dennis Cogan, a veteran Philadelphia homicide prosecutor now in private practice, is among those who say the one-sided arrangement is a relic that was phased out in other major cities long ago.
"Suffice it to say that this is not a modern charging system," he said. "And it is certainly not the way it is done in federal court, where the prosecutor is engaged at the outset of the investigation and has his or her name and reputation on the line if they bring a crap case to trial."
In those jurisdictions that follow the federal model, prosecutors assume control of the case early on and share supervision of the investigation with police commanders.
Not so in Baltimore.
The result: The state's attorney's office has dropped charges against a stunning 23 percent of first-degree murder suspects over the past five years.
"Number one," says Judge Prevas, "it is the department that is not giving the prosecution a good case."