KCRA The 12-year-old brother of Leila Fowler, shown in a screen grab from video, was arrested Saturday on murder charges in her death.

The 12-year-old brother of a California girl found stabbed to death in their home last month was arrested Saturday, authorities said.

Calaveras County Sheriff Gary Kuntz told reporters that Leila Fowler's brother, who had said that an intruder killed her, was taken into custody after a two-week investigation. Kuntz said the boy would be charged with homicide, NBC station KCRA of Sacramento reported.

The 8-year-old girl and her brother were home alone on the afternoon of April 27 at their Valley Springs home when she was killed, KCRA reported, citing school district superintendent Mark Campbell, who met with the parents. The parents were at a Little League game in the small town at the time of the attack, Campbell said.

Officials said at first that Fowler's brother told them he had found her body and described her killer as a tall man with long gray hair. The county coroner told KCRA that Fowler died of shock and hemorrhaging caused by multiple stab wounds.

Authorities searched the home and neighborhood, while dive teams searched two reservoirs near the house. A neighbor who told authorities a man ran from the home was discredited, KCRA reported. Investigators have said there was no sign of a burglary or robbery.

Her death and her brother's account of a murderous intruder put the town of about 7,400 on edge.

"Nobody is staying alone," parent James Barci told KCRA in April.

Barci, a truck driver, who is a volunteer at Jenny Lind Elementary School, where Leila was a popular third-grader, added: "I told my work I'm not coming in, and I'm just going to have all of my kids' friends at the house until this is over." And Sheriff Kuntz said then: “We will not rest until we capture the responsible person.” In a statement issued Saturday, Kuntz did not reveal what evidence led to the arrest. But NBCBayArea.com reported that he said at the news conference: "Citizens of Calaveras County can sleep a little better tonight."

Rich Pedroncelli / AP Teacher Cecilia Richardson helps a student tie a ribbon honoring third-grader Leila Fowler, at Jenny Lind Elementary School in Valley Springs, Calif., on April 29.

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