(CBS) - When 18-year-oldallegedly murdered his mother, sister, and mother's boyfriend in Weymouth, Mass. last week, he probably didn't know that he was becoming part of a gruesome trend in American killings.
Last week, the federal government released its most recent homicide data and murder is down in virtually every place but one: at home. Between 1980 and 2008 the number of children killing parents and parents killing children has remained steady, and even gone up slightly.
That doesn't surprise Kim Slayton White, the head prosecutor in Halifax, Va. White recently tried the case of Dylan Wynn, a 16-year-old boy who shot and killed his father in April. Before becoming a prosecutor, White was an assistant public defender who helped represent Sandra Moneymaker, a 36-year-old woman who killed her two sons and then shot herself in 1991.
White sees these familial homicides as "special."
"There are so many emotions and internal dramas at work in a family that don't get changed by anti-gang measures or tough drug enforcement," says White.
Forensic psychiatrist Dr. Phillip Resnick, who has testified in numerous family homicide trials including the case of Andrea Yates, the Texas woman who drowned her five children in a bathtub in 2001, agrees that the "family dramas" that lead to murder aren't affected by things like advances in policing, which many experts credit with helping bring the overall crime rate to a 40-year low.
And according to attorney Paul Mones, the author of "When A Child Kills: Abused Children Who Kill Their Parents," murders within families rarely follow other trends in homicides.
"When homicide skyrocketed in the 1980s, [family homicide] stayed about the same," says Mones, "and when the numbers started going back down in 1996, they stayed the same." Mones says that each week, approximately five children kill their parents in the United States, for a total of between 250 and 300 annually.
Mones says the factors that often lead to a child killing his parent tend to be abuse and "severe family dysfunction."
A look at just a few recent cases bears this out:, 15, who stabbed his grandmother to death in Chicago on November 4, had reportedly been diagnosed with bipolar disorder and was in his grandmother's custody due to his mother's drug problem.
In Conyers, Ga., where 16-year-old twinsare accused of stabbing and beating their mother to death in January 2010, Rockdale County District Attorney Richard Read told Crimesider that the girls came from "four generations of family dysfunction."
And in the aforementioned Virginia case of Dylan Wynn, prosecutor Kim Slayton White says that the boy was a victim of a mentally and physically abusive father, as well as a manipulative mother and grandmother who goaded the teen into killing his father. In that case, the mother and grandmother were also found guilty of murder and the jury recommended between 23 and 35 years for them, respectively. Dylan was sentenced to just a few years in a juvenile facility.
"We realized that in this case, Dylan was truly as much a victim as his father was," says White.
Mones says that in homicides where children kill their parents, there is often an element of "overkill" stemming from an "emotional overreaction" which outrages the community and catches media attention. Wynn shot his father while he slept on the couch. In 2004, 14-year-old Nakisha Waddell was convicted of stabbing her mother 43 times and burying her in the backyard of their Wythe County, Va., home.
When it comes to parents killing children, Dr. Resnick says that depression and other mental illnesses often play a roll. He also says he believes that the hard economic times might be a factor in the slight increase in this type of homicide. According to the Bureau of Justice Statistics, among homicides committed within families, parents killing children jumped from representing 15 percent in 1980 to 25 percent by 2008. The Bureau report says cases of children killing parents constituted 9.7 percent of all family homicides in 1980, and rose to 13 percent by 2008.
"I could anticipate an increase in these crimes with the bad economy," says Resnick, who describes possible scenarios including "unemployed, irritable" parents home alone with children, child welfare departments missing warning signs because of too many cases and tight budgets, and suicidal parents who decide to take their children with them in death.
Chillingly, these scenarios are reflected in two recent cases:
In Cincinnati, 2-year-oldwas allegedly beaten to death by his father on October 21; the boy had been in foster care, but was returned to his parents just two months before his death. In October 2010, 28-year-old Monica McCarrick was charged with murder after she allegedly stabbed her 3-year-old twin daughters before turning the blade on herself and then setting the family's Fairfield, Calif., apartment on fire; the children were killed and McCarrick survived.
Unfortunately, some of the things experts say could prevent these kinds of tragedies - better access to mental health care for children and their parents, access to affordable child care, and stronger child welfare investigations, for example- are unlikely to be instituted in a time of state and federal budget cuts.
Virginia prosecutor Kim Slayton White says that, sadly, she doesn't see a light at the end of the tunnel for these killings any time soon: "I think the tough economic times we're going through have a huge impact on people and do real harm to family relationships."