* Steven Ward, 16, of Lowell, was convicted of the beating and stabbing death of 73-year-old Louis Pozycek, of Lowell, on Sept. 18, 1988.

* Daniel LaPlante, 17, Townsend, raped and murdered nursery school teacher Patricia Gufstafson of Townsend and drowned her two children on Dec. 1, 1987.

* Joseph Donovan, 17, Cambridge was one of three teenagers who were charged under a joint-venture theory in the stabbing death of Yngve Raustein on Sept. 18, 1992. Donovan threw the punch that knocked Raustein to the ground.

* Edward O'Brien, 15, Somerville fatally stabbed his best friend's mother on July 23, 1995. He was initially to be tried in juvenile court, but public outcry about the possibility of a lenient juvenile sentence led lawmakers to quickly pass the tough new law aimed at punishing "adult crime with adult time." Under that law, a teen convicted of first-degree murder must serve life in prison without any chance of being released.

* Donnie Bouhpavongsa, 16, Lowell, and six other young men beat 17-year-old Joshua Molina, of Lynn, to death with hammers, shovels and "The Club" on Nov. 20, 1997, as Molina and two friends walked along Bridge Street.

* Noeun Sok, 16, Lowell chased Keoudone "Tiny" Onexavieng, 18, down the street and put a 30-inch samurai sword in his back, killing him on Jan. 12, 1999.

* John Odgren, 16, Sudbury, fatally stabbed Lincoln-Sudbury Regional High School classmate James Alenson in the boys' bathroom on Jan. 19, 2007.