Jeffrey Hunsberger and his wife, Michelle Legere, of Eden Mills, Vt., say they heard no warnings about having a safe sleep environment before their son, Simon, died in bed with them in August 2005. They're shown here with daughter Sophie, born in November 2006. In Simon's memory, they've set up a foundation both to aid other grieving parents and to promote safe sleeping practices. (SHNS photo courtesy Jeffrey Hunsberger)

James McKenna, an anthropologist at the University of Notre Dame, lectures at a recent meeting of the American Anthropological Association. After nearly three decades studying how babies and mothers sleep together, McKenna says he doesn't advocate bed-sharing for all families, but strongly objects to efforts by public health officials to stigmatize or criminalize the practice. "It's ethically wrong ... to take the decision out of the hands of parents," he says. (SHNS photo by Lee Bowman.)

Dr. Rachel Moon, a pediatrician at Children's National Medical Center and George Washington University who studies infant sleep risks and bed-sharing, shown here in a sleep lab at the hospital, says there are clear links between sudden infant deaths and sharing a bed. She's helping to lead a new research project to study if crib distributions and safe sleep education bring down unexplained baby deaths. (SHNS photo courtesy Children's National Medical Center)

Pittsburgh-based Cribs for Kids was founded in 1998 after the local child death review team noted that most sudden infant deaths were happening in unsafe sleep settings. The program has distributed 6,500 cribs, and has established 152 branches in 33 states in just the past 18 months. From left, around the demonstration crib at the office of Sudden Infant Death Services of Pennsylvania, are Eileen Collins, director of support and education, Judith Bannon, executive director and founder of the project, and Barbara Clemmons, crib distribution manager.

Linda Norton, a forensic pathologist from Dallas, said it is easy for infant homicides to be mistaken for Sudden Infant Death Syndrome. (SHNS photo courtesy Linda Norton)

Rep. Frank Pallone, D-N.J., who chairs the House Energy and Commerce Subcommittee on Health, said a study by Scripps Howard News Service has convinced him to begin congressional discussions with the national Centers for Disease Control and Prevention "to see how we can improve the accuracy of the data and, therefore, our response to the tragic problem of infant deaths. This study clearly shows that a more accurate and aggressive approach to children's death reviews is needed," (SHNS photo courtesy the National Governors Association)

San Pablo police officer Jose L. Barajas, age 37, is photographed on Friday, November 9, 2007 in San Pablo, Calif. Barajas is a ten year veteran of the San Pablo Police Department. Currently Barajas is working as a patrol officer but before that he was a detective. While as detective he solved two child murders that were originally classified as SIDS. (SHNS photo by Jose Carlos Fajardo / Contra Costa Times)

Deborah Robinson of Kirkland, Wash., an infant-death specialist with the SIDS Foundation of Washington, in a lab at the University of Washington, one of the nation's top centers for research on the causes of sudden unexplained infant death for more than four decades. Despite Washington state's long support of investigating and researching infant deaths, she says many investigations and even autopsies of babies who die mysteriously are incomplete, leaving gaps in data both for research and teams that review deaths. (SHNS photo by Steve Szugschwerdt / The Bremerton Sun)

Melissa Haberzettl, 29, of Colorado Springs, Colo., knew something was wrong when the county coroner ruled that her 3-month-old son, Jake, died of viral pneumonia in February. Death by pneumonia is very rare for otherwise healthy infants.

"My husband and I are both physical therapists, so we have many connections in the medical field who all agreed with us that this was a ridiculous diagnosis," Haberzettl said.

Angie Steffke's 8-month-old son, Owen, became part of a new and disturbing pattern for infant death when he died in his Indianapolis, Ind., home on Oct. 6, 2003.

Owen, according to records sent to the Centers for Disease Control and Prevention, officially died of "other ill-defined and unspecified causes of mortality" as well as of "coma, unspecified."

Officially, Owen died of a mystery.