PHILADELPHIA (CBS)–A confession in the Solebury murder investigation does not draw a close to this excavation.

The intensive search for human remains will likely continue on the 90-acre Solebury Township property owned by the family of confessed killer, Cosmo DiNardo.

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The mystery of the four men’s disappearances transfixed the Philadelphia area over the past week, took a grisly turn when human remains were discovered in a 12½-foot-deep grave on the farm.

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That’s where the body of Dean Finocchairo  was found, along with additional remains that have yet to be identified.

“Obviously someone who is digging that hole is digging with heavy equipment… He didn’t.. in the span of time that had elapsed he didn’t dig that hole by hand, not up here, not in this soil,” said JJ Klavier, a former FBI special agent.

Klaver says that while he believes heavy equipment was used to form the 12-foot grave, investigators must take a more delicate approach.

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“It has to be really almost by hand you can’t just bring in heavy equipment and start digging.”

Klaver says investigators will continue their efforts until all human remains in that grave are recovered, along with evidence that can corroborate what DiNardo has told police.

“It’s a crazy thing man I mean I can’t even believe it,” said Daniel Balbuena, who worked with Dean Finocchairo .

“The only reason that I am not crying right now is because if I cry dean is going to be mad at me like, ‘Don’t cry for me bro.’

More friends have written notes of mourning on construction paper and are planning to give it to Finocchairo’s family.

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