GERMANTOWN, MD - JANUARY 19: A makeshift memorial at the scene of the double murder includes a heart shaped balloon.The home where two children were killed in what the mother says was an attempted exorcism. (Michael S. Williamson/The Washington Post)

THE NUMBER of homicides in the District was slightly up last year while there was a decrease in Prince George’s County and a doubling in Montgomery County. But the numbers (105 in D.C., 56 in Prince George’s County, 18 in Montgomery County) tell just part of the story of the lives taken in violence.

It is the stories — of two toddlers suffocated in Cheverly, a 51-year-old D.C. woman strangled by her husband during an argument over an unpaid cable bill, a Gaithersburg 7-Eleven clerk repeatedly stabbed in what police called an unprovoked attack by a deranged customer — that reveal some of the forces fueling homicides. Even as they expressed cautious confidence about efforts to fight street violence, law enforcement officials in the region expressed concerns about a spike in killings linked to domestic violence and the ever-growing connection between crime and mental health.

Perhaps the most heartbreaking statistic was the number of young children killed last year, the majority by a parent or guardian. Seven children were killed in Prince George’s, four children — all 3 years old or younger — were slain in the District, and three toddlers were victims of homicides in Montgomery. Not included in those numbers are 8-year-old Relisha Rudd, 3-year-old Sarah Hoggle or 2-year-old Jacob Hoggle. All went missing last year and are feared dead. “Every murder is a concern,” Prince George’s County State’s Attorney Angela Alsobrooks told us, “but it is the kids that keep you awake.”

Prince George’s noticed the spike in family violence in 2013 and put new strategies in place, including involving the faith community. But Ms. Alsobrooks said still more needs to be done. She wants to target men in domestic violence public-information campaigns and let children know about the need to report violence in the home.

So alarmed is Montgomery County State’s Attorney John McCarthy about the threat posed to public safety by unaddressed mental health issues — as evidenced by the unusual number of homicides last year involving people with mental illness — that he’s tapped former county council member Phil Andrews for the new job of director of crime prevention initiatives. Mr. Andrews said he plans to work across agency lines to come up with and put in place best practices. Montgomery is on the right track in recognizing that this issue must be attacked not just by law enforcement but also by public and private social agencies.

In looking back at 2014, the Washington area can be grateful that the awful days of homicides numbering in the hundreds and the District being described as the nation’s murder capital are things of the past. That, though, cannot detract from the pain of each life lost or the need to do better in preventing future homicides.