The BBC teen homicide database, which records murder and manslaughter cases, shows 51 10 to 19-year olds lost their lives in 2009 compared with 72 in 2008.
Most 2009 victims were male and half of all those killed were stabbed. Twelve were beaten and two were shot.
Police say anti-knife crime tactics explain the drop, but critics argue it is too early to make such conclusions.
Latest victim
The BBC News website's database shows that of the 51 young people killed so far this year, the youngest was just 10 years old and the oldest 19. The most common ages of victims were 17 and 18.
Most of the victims were white and male - just nine of the 51 were girls.
Any stats on whether most of the killers were white and male?
The BBC teen homicide database, which records murder and manslaughter cases, shows 51 10 to 19-year olds lost their lives in 2009 compared with 72 in 2008.Most 2009 victims were male and half of all those killed were stabbed. Twelve were beaten and t