The girl was killed on Saturday at a house on Rippon Road in Valley Springs, California, a town about 60 miles from Sacramento, according to the Los Angeles Times. Police asked residents of Calaveras County, California, to lock their doors.
"We were doing a house-to-house search and in some cases we're searching extensively into attics and storage sheds," Calveras County officer Jim Macedo told CBS Sacramento. "It's a difficult area to search. It's rural, it's remote."
The girl's 12-year-old brother was also in the home when the attack happened, according to reports. The boy encountered the intruder around noon on Saturday and he immediately fled. The boy then called 911 when he discovered his sister had been stabbed and she was pronounced dead later.
Neighbors described seeing the man escaping shortly after the 911 call, according to multiple reports.
It appears that police are looking for a white or Hispanic male with long gray hair, at least six feet tall and wearing a black long-sleeved shirt and blue pants.