VALINDA ( — Following up on a tip, Los Angeles County Sheriff’s detectives and personnel from the L.A. County coroner’s office were digging for human remains in the backyard of a residential home in the San Gabriel Valley on Thursday, hoping to make progress in a six year old cold case.

In the tip, homicide detectives were told a person was buried in the backyard of a home on the 700 block of Elsberry Avenue in Valinda. Authorities arrived at the scene around 7 a.m. and began painstakingly sifting through the backyard soil for any evidence of human remains. The investigators are looking for the remains of a person who has been missing since 2009, although the name of the missing person in questions has not been disclosed.

Many hours into the search, at about 4 p.m., authorities were deciding whether to switch on lights to allow the digging to continue into the night, CBS2/KCAL9’s Dave Lopez reports.

Authorities said the current residents of the home are not part of the investigation and have been cooperating.