D.C. police Cmdr. Chanel Dickerson, head of the Youth and Family Services Division, explains new criteria for publicizing missing persons on the police Twitter and other social media accounts. (Peter Hermann/The Washington Post)

The alerts from D.C. police streamed quickly over the department’s Twitter account. Seven people gone missing in a single week in March. All but one were children between the ages of 13 and 15, and most were girls. Authorities included their names and photos and labeled each case “critical.”

Police created the urgency they sought, and four of the missing were quickly found. But the alerts also raised concern on social media and in some of the District’s most troubled neighborhoods that children — young African American and Hispanic girls in particular — were vanishing from city streets with little outcry from the public or law enforcement. Some expressed fear about human trafficking.

On Thursday, the District’s mayor and acting police chief held a news conference to explain that there is not a rash of missing-persons cases, but police are increasingly using social media to help find people. Police have begun to publicize every missing person in the District whose case is deemed “critical.” That definition includes anyone age 15 and under, including chronic runaways, and people 65 and over. In the past, publicizing such cases was discretionary.

The acting police chief, Peter Newsham, who is awaiting confirmation, said nearly everyone reported missing is found safe. He said there is no evidence to suggest any of the recent missing person cases are related or linked to human trafficking. But, he said, the stepped-up use of social media “has drawn an increased awareness of the number of missing persons we have in our city.”

At the same time, police said the number of missing persons reported in the District is declining. Statistics show that about 190 juveniles have gone missing each month this year, down from about 200 a month in 2015 and even more in 2012. This year, 708 people have been reported missing, 462 of them juveniles, and, as of Thursday afternoon, 674 have been found.

Police said 18,772 people were reported missing between 2012 and 2016, and that 16 cases remain open.

“The overwhelming majority are closed because most of the reported missing in D.C., juvenile and adult, have decided not to check in at home, at work or at school,” said Police Cmdr. Chanel Dickerson, who oversees the Youth and Family Services Division, which includes the missing person squad.

Dickerson, who was promoted to commander in December, said she was alarmed by the number of missing person cases in the District, which according to the National Center for Missing and Exploited Children is on par with other cities across the country. Dickerson said she wanted to make it “a priority to give the same level of attention to each and every case.”

Outright abductions of children are rare, especially by strangers. But those who leave voluntarily also can be in danger. Authorities say runaways seeking help may be targeted by human traffickers.

The District’s most pressing case remains that of Relisha Rudd, the 8-year-old girl who disappeared in 2014 with a janitor at a homeless shelter where she lived. The janitor was found dead of an apparent suicide; Relisha has not been found. Her family had allowed her to spend time with the janitor, and police say they think that Relisha was killed.

D.C. Council member Charles Allen (D-Ward 6), chairman of the Public Safety Committee, said in a Facebook post that “even if there’s no increase” in the number of missing persons, “the fact that we have so many teens and young people go missing should be a cause of concern.”

Robert G. Lowery Jr., vice president of the missing person division of the National Center for Missing and Exploited Children, said he wished other police agencies would copy the District’s approach. “Engaging the public is our best and strongest way of getting children reunited with their loved ones,” he said.

Dickerson said she still hopes the publicity will continue to help police find the missing more quickly.

“It’s heartbreaking to see the number of young people in our city who leave their homes because they feel there is no other alternative,” she said. “I want to let them know they are valuable assets to our community. We have not counted them out or written them off. We are here to help them.”