Investigators searching for little Robert Manwill, an 8-year-old boy with an impish grin, said today they fear he may have been the "victim of a tragic event."
"Investigators from the Boise Police Department, with assistance from the FBI have located evidence that may bring us closer to finding what happened to Robert," said Boise's Deputy Chief Jim Kerns.
Kerns said the evidence was discovered in a search Thursday night of the boy's mother, Melissa Scott Jenkins.
"The evidence we've uncovered shows there are suspicious circumstances regarding Robert's disappearance," said Kerns. "Robert may be injured."
The boy's mother is divorced from his father, Charles Manwill. The father has custody of boy who was on an overnight visit to his mother.
Pictures of the little boy with the mischievious grin have been plastered all over the city. Volunteers have mobilized by the hundreds.
Yet there is, so far, no sign of Robert Manwill.
The July 24 disappearance of the 8-year-old has touched off what police say is among the largest searches in the city's history. Everyone is being scrutinized, they said, including the boy's own family, which has a seemingly violent history.
His parents haven't said much of anything to the public. Jenkins has two other children and lives with a boyfriend.
Court documents show that Jenkins and her boyfriend Daniel Ehrlick were taken to court by the state for child support relating to an unnamed child in foster care.
Jenkins is on probation after being charged with felony injury to a child, a charge the Idaho Statesman reported came after she fractured the skull of Robert's infant half-brother who was removed by the state.
The paper also reported this week that Ehrlick has served time in prison and been convicted of battery and burglary. According to the Statesman, Ehrlick is banned from spending time alone with Robert's half-sister.
Police have kept mum so far on the family's legal troubles and their involvement with the search for Robert.
"The previous family history and the connection to Robert's case, if any, is ... part of the investigation," Boise Police spokeswoman Lynn Hightower told ABCNews.com.
Robert's aunt, Trisha Burrill has been acting as the family's spokeswoman. She told ABC's Boise affiliate KIVI that the family's troubled history should not be a focus for police or the media.
"We do not know why people think any of this matters," she said. "We are asking everyone to stay focused on our target on hand and that's to bring Robert home."
KIVI reported today that Boise police spent hours at Jenkins' home Thursday, towing the family's car and leaving with bags of evidence.
Robert was reported missing from his Boise Bench apartment complex shortly after 10 p.m. July 24. He was last seen wearing a faded blue T-shirt with a Superman design, blue jeans and dark tennis shoes.
Sex Offenders, Apartment Complex Checked During Search
Hightower told ABCNews.com that about 140 registered sex offenders live within a 2 mile radius of Robert's home in a working-class neighborhood of the city and that each one has been visited.
"Some of them have been checked and re-checked and re-checked," she said, adding that police will continue to revisit those people and others as the search continues.
In addition to the hundreds of volunteers expected today for a massive search effort, police have even drained a 6-foot deep landscaping pond in the apartment complex.
"There was no indication he was in there, but as a precaution, it was drained," she said.
The FBI and the Idaho State Police are among the numerous agencies that have been called into assist.
No Amber Alert has been issued in the case because police can't be sure Robert was even abducted. Hightower declined to comment when asked if Robert had a history of running away from home in the past.
"At this point, until we find Robert, anything is on the table," she said.