A search is underway at a construction site in Northeast Washington for Relisha Rudd, missing since March 2014. (Bill O'Leary/The Washington Post)

The latest attempt to find the remains of missing child Relisha Rudd ended in failure Thursday after police cadets fanned out across a desolate construction site in Northeast Washington near a hotel that was one of the last places the girl was seen with her abductor.

D.C. police would not say what drew them to a 15-acre, ­triangular-shaped lot off Bladensburg Road and New York Avenue. Up to 80 searchers and K-9 dogs trained to smell cadavers combed through weeds and over mounds of hard red clay for five hours before police announced that they had found nothing of significance. Police said they plan to search a second, undisclosed site at a later date.

In the end, it was another sorrowful moment in a thus-far fruitless search that began 21 months ago, when Relisha disappeared with the janitor of the homeless shelter at the old D.C. General Hospital, where she was living with her family. Relisha was 8 years old at the time; she would have turned 10 in October.

D.C. Police Chief Cathy L. Lanier wouldn’t offer specifics but said Thursday that police had received some additional details, looked at videos and talked to those who last saw Relisha with the now-deceased janitor, Kahlil Malik Tatum. ­Lanier said the search was complicated because of the length of time Relisha has been missing.

Police found no sign of Relisha Rudd during a search at a lot off Bladensburg Road and New York Avenue on Dec. 10. Rudd, who would have turned 10 in October, went missing nearly two years ago. (WUSA 9)

“It gets more difficult every single day,” the chief said as she stood at the 5th District police station, across the street from the construction site’s entrance. “It doesn’t mean we stop looking.”

Police efforts to find Relisha have focused on several areas of the city. After unsuccessfully searching the 700-acre Kenilworth Park and Aquatic Gardens in March 2014, police all but declared Relisha dead and described further searches as recovery missions.

In that earlier search, however, police found Tatum’s body in a shed at the park. Police said he had committed suicide after abducting the girl and killing his wife in a Maryland hotel room. They said that Tatum, 51, had bought large trash bags and was seen on surveillance video at a Holiday Inn Express across the street from the construction site where authorities were Thursday.

Relisha’s mother, Shamika Young, said she didn’t know what prompted the latest search. The police haven’t spoken to her about new leads in the case, she said.

And she still doesn’t believe that her daughter is dead.

“I do believe she’s alive,” she said. “I don’t care what other people say. That’s my kid.”

Young has long had a contentious relationship with city authorities, who accused her of misleading them about Relisha’s whereabouts when the second-grader was discovered missing. Relisha’s three younger brothers have been in foster care for almost two years, and a court is still considering whether to terminate Young’s parental rights.

D.C. police photograph potential evidence as they continue the search for the remains of Relisha Rudd in a construction site. (Bill O'Leary/The Washington Post)

Young expressed bitterness toward police investigators, insisting that they haven’t done enough to find her daughter. She is scheduled to see her sons.

On Thursday morning, Lanier said the search could last at least two days, but it wrapped up more quickly than expected.

The construction lot was once considered for a Walmart store and was more active at the time Relisha went missing in March 2014.

Police said at the time that a fence that now surrounds the area was not there, allowing easy access.

The lot has sat empty for months. It slopes downward from Bladensburg Road and has large expanses of barren clay that police said makes digging difficult.

Deep trenches cut through the property, and there are clumps of weeds and dead trees. There is a pile of concrete from a demolished building, and debris litters the yard.

The cadets spread out at arm’s length and trod over the lot, stopping at anything that looked suspicious or interesting — such as a discarded sweatshirt — and marking them with red ribbons.

About 11 a.m., searchers stopped in a rugged area near a paved path close to Bladensburg Road. One officer made a call on his phone, asking for help to “dig up a bag.”

A van from the medical examiner’s office arrived, and three investigators hovered around a spot near a scraggly tree. A police officer took a rake and shovel from the back seat of a cruiser and carried them to the spot.

Authorities brought in several backhoes and other construction equipment, planning at one point to take apart the concrete pile. But police later said that the K-9 dogs smelled nothing as they roamed over the pile.

Lanier said that police will not stop searching for Relisha until all leads had been exhausted.