Police confirmed late on Thursday that the person they arrested in Herne, North Rhine-Westphalia is the main suspect, 19-year-old Marcel H.
Authorities also confirmed that they had found a dead body in an apartment, correcting an earlier press release which stated that two bodies had been found.
On Monday the nine-year-old boy, Jaden, was found dead with stabbing wounds in Marcel H.'s basement in Herne, but the 19-year-old had apparently fled. According to the lawyer for Jaden's family, their neighbour Marcel H. had lured the boy over under the pretext of helping him hold a ladder.
Photos of Marcel H. surfaced online, depicting him with bloody hands next to a body.
The boy's apparent murder prompted a nationwide search, involving helicopters and sniffer dogs. Police received more than 1,400 tips during the course of the search.
The man also told police about an apartment fire in the town. When officers arrived at the location, they found a further dead body. Police are still interrogating the man.
"[The victim's] family is infinitely relieved and happy that the suspected murderer of little Jaden could be caught alive, and can be given his just punishment," the family's lawyer told Bild.