Philadelphia police and one of its K-9 units were seen searching the Bucks County farm of Cosmo DiNardo's family, according to FOX29.
DiNardo admitted to killing four young men on the Solebury Township property in a homicide case that received national attention. But during his confession, he also claimed to have killed two people in Philadelphia.
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Philadelphia Police Commissioner Richard Ross told the Associated Press the information was "sketchy," and that they would have to deal with DiNardo directly in order to investigate the claims.
Philly police were seen on the DiNardo's 90-acre farm around 10:30 a.m., FOX29 reports. An assignment editor at CBS Philly posted video of the police vehicles on the property to Twitter.
DiNardo is charged with killing Jimi Taro Patrick, 19, Dean Finocchiaro, 19, Mark Sturgis, 22, and Tom Meo, 21, after allegedly luring them to his farm to buy marijuana.
His cousin, Sean Kratz, 20, is charged in three of those killings.