Precious few clues in VA killing-kidnapping

A family photo of Jennifer Renee Short

BASSETT, Virginia (CNN) -- The sheriff heading the hunt for a 9-year-old southwestern Virginia girl said Saturday evening that investigators have no new leads despite nationwide appeals and publicity.

The search for Jennifer Renee Short has extended across Virginia and as far away as Florida, said Sheriff Frank Cassell.

Cassell said that the publicity surrounding the case and appeals for information had produced "lots of response," but so far nothing that had led to Jennifer.

Police issued new photographs of Jennifer, daughter of 50-year-old Michael Wayne Short and 36-year-old Mary Hall Short, who were found murdered in their home in Henry County, Virginia, Thursday.

At an evening news briefing, Cassell repeated his earlier assertion that whoever killed the girl's parents and abducted her was "someone the whole family knew."

" I feel, and I think most of the investigators feel, and we may be wrong, that this crime was committed by someone who knew this family," he said.

Early Saturday, officials suspended a 200-volunteer search effort that covered 100 square miles but failed to produce any evidence.

Jennifer's parents were found dead -- the father on a couch and the mother in her bed. Cassell said earlier that preliminary autopsy results confirmed that each of the parents died from a single gunshot wound to the head.

Cassell did not explain why he believed the killer or killers knew the victims, and said that authorities had questioned "dozens of people so far" but had no new information.

CNN NewsPass VIDEO CNN has obtained this exclusive home video of the missing 9-year-old girl, Jennifer Renee Short, whose parents were recently killed. (August 17) Play video    CNN NewsPass Video    •  Westerfield case enters sentence phase  MORE STORIES   •  Body of missing girl's father exhumed   •  More arrests in California boy's kidnap   •  Ricci's widow: Police had the wrong man   •  Smart's dad: More than one person took daughter  RESOURCES   •  Gallery: Technology to keep children safe   •  Safety experts offer tips   •  Facts: Missing children   •  Gallery: Recent missing youngster cases   •  AMBER Alert System  EXTRA INFORMATION   •  TIME.com: Keeping your children safe   •  National Center for Missing & Exploited Children

"It's frustrating, but we persevere," the sheriff said. "But obviously, the longer the time frame, the more desperate it becomes."

Exhaustion and a lack of evidence led Old Dominion Search and Rescue team commander Richard Cox to suspend the efforts of about 200 volunteers. He said the search, which had covered about 100 square miles around the Short home, ended at 4 a.m. EDT Saturday.

Cassell said the official investigation, now involving more than 40 local, state and federal law enforcement officials, would continue unabated and stressed his optimism.

"Until we find the worst we hope for the best," he said.

The killings and abduction have shocked the town of 1,300 in southwestern Virginia.

"This is a very unusual case. We don't see many like this," Cassell said. "We've had a lot of horrific murders, but I don't remember a genuine child abduction in this area."

Cassell said authorities have interviewed Christopher Thompson, the man who discovered the slain parents, and would likely do so again. But Thompson has provided no new information, he said.

Thompson worked for Michael Short and had been at their house the night before, working on a vehicle, Cassell said. Thompson has told investigators the parents were alive when he left the home around midnight and that the girl was in her bed.

"So far, he's been very cooperative," Cassell told CNN.

Authorities have said little about the crime scene, such as whether there was any sign of forced entry or any sign of a struggle inside the house. But Cassell said nothing appeared to be missing from the home, apparently eliminating robbery as a motive.

Jennifer has brown hair, is 4 feet 3 inches tall and weighs 58 pounds.

With the focus on saving the girl, an "Amber Alert" -- named after a 9-year-old girl abducted and killed in Texas six years ago -- was issued for Jennifer, with billboards and signs posted throughout the state urging Virginians to be on the lookout for the girl.

-- CNN Correspondent Jeanne Meserve contributed to this report.