Sources tell ABC7 News that the person authorities believe may be responsible for Collins' abduction is now deceased, but was living in the Page Street lower flat when the boy disappeared. Police have been digging in the backyard and basement in the hopes of finding the remains of Kevin Collins.
Almost 30 years ago, Collins left basketball practice at St. Agnes School in the Haight and waited for a bus at Oak Street and Masonic. That was the last place he was ever seen. Collins was 10 years old when he disappeared and he was one of the first missing children whose case got national attention.
Thousands of tips have come in over the years, but they all led nowhere.
Tuesday, the cold case unit brought in a cadaver sniffing dog, which found something in the basement floor. City crews brought in a jackhammer and began digging through a portion of the concrete. A crew from the medical examiner's office was called in when bones were discovered in the ground. Police say they believe they are animal bones, but they will be sent to a state laboratory to determine if they are human or animal remains.
Kevin's mother, Ann Collins, told ABC7 News on Tuesday night the family would have preferred some form of closure in the case, but a final determination on the bones still has to be made. Ann is getting calls and emails of support. When we asked her how she felt about this latest news, she told us, "Partly relief that it's animal bones, partly sorry that it's not closure, especially for my children and grandchildren."
Homicide inspectors were eyeing the backyard of the home at least a month ago, looking from an adjacent porch and taking pictures from a nearby bedroom, according to next door neighbor Emma Marson.
"They like showed me their badges and they said, 'We just need to see if you have a view into your neighbor's backyard,'" said Marson.
Police emphasize that the current residents of the home have nothing to do with the case.
ABC7 News also spoke to Kevin's brother, Steven, on Tuesday night. He says he and the family are cautious about getting their hopes up because they have been let down many times before.
In an unrelated investigation in October 2012, Dan Noyes and the ABC7 News I-Team discovered a possible connection between a serial killer and the Collin's disappearance. ABC7 News took a look at the confession tapes of a death row inmate who confessed to killing three other boys, a serious lead San Francisco police either missed or chose to ignore.
ABC7 News reporter John Alston contributed to this report.