ROSEVILLE, Mich. -- A ground sample taken from inside a shed Friday on a Michigan driveway shows no evidence of a body in the search for Jimmy Hoffa, the city's police chief said.

The 4-inch core sample pulled out from six feet under a concrete slab was just a combination of clay and mud, Police Chief James Berlin said. Results from analysis of that core sample and one more are expected back from Michigan State University on Monday, he said.

"We'll have to wait for the test results back from Michigan State," Berlin said. "The sample's muddy clay, so there's nothing visible that would indicate evidence of a body."

A man who has lived in the 1,000-square-foot brick ranch in Roseville with his mother since 1990 said investigators approached the family a few days ago. The resident, who would not give his name, said investigators claimed to have a "tip" that a body might be buried under the shed, but didn't specifically mention Hoffa.

"Anything's possible," the man said. "I mean, we've seen stranger, haven't we?"

He said he and his mother hope things return to normal on their quiet street after the drilling, the incessant calling and the media frenzy outside.

"She just wants to relax now," he said of his mother. "She's been shaky. She's tired. She hasn't had much sleep."

A white State of Michigan box truck pulled up at about 9:30 a.m. next to the house. By 10 a.m., a portable hydraulic drilling machine was inside a shed in the backyard. Staccato pounding periodically ran out over the rumbling of a generator in the back of the Gator pulling it.

Berlin went through a series of interviews by CNN, NBC and the "Today" show as well as local newspaper, radio and television stations.

Berlin said the owner of the home around the time of Hoffa's disappearance in the 1970s was a bookmaker with ties to members of Detroit-area organized crime, the alleged prime suspects in Hoffa's disappearance.

About 150 media people and gawkers filled the sidewalk and blocked-off street next to the nondescript brick bungalow to watch the drilling.

Natalie Vessella, 27, said her 3-year-old daughter, Sadie, and 1-year-old son, Jackson, pointed out the noisy news helicopter flying above their house a couple of blocks away. So she packed them, a couple of sippy cups of apple juice and some cinnamon cereal squares in the double stroller and walked over.

"I told them they're looking for hidden treasure; I couldn't tell them why," said Vessella, one of a few mothers watching the spectacle with kids in tow. "This is history. Well, could be history."

Chrysler worker Dennis Delpier, 57, who retired after 30 years on the line at the Sterling Heights assembly plant, rode his bike from about a mile away to check out the scene.

"Ahhhhh, could be, could not," he said about Hoffa being found buried under the concrete inside the tan, barn-like shed. "I'd say he's down in the Renaissance Center. You know how many concrete footings are down there?"

Jerry Jeup, 73, born and raised in Roseville, drove over to watch the drilling take place.

"I really don't know," he said, adding that he knew the family that lived in the home in the '70s around the time of Hoffa's disappearance. "There's a possibility. At some point, it's got to end. Will they ever find him? I doubt it."