A plumber accused of slitting a woman's throat outside her secluded home and dumping her body in a lake was arraigned on murder, kidnapping and larceny charges Monday afternoon as authorities continued the search for the mother of three.

A Macomb County judge entered a not guilty plea on behalf of David J. Wright, assigned him a lawyer and ordered a preliminary examination to be held July 3. Wright was being held without bond in the Macomb County Jail.

"These are two of the most serious and egregious crimes in the book," Macomb County Prosecutor Eric Smith said in asking that no bond be set.

Meanwhile, divers on Monday searched for the body of Marilou Johnson in Cass Lake in neighboring Oakland County.

"We got some great information that was substantiated by the actual person we have in custody that her body is in this lake," Macomb County Sheriff Mark Hackel said. "It depends on where he took her and where he paddled her out to."

Asked if investigators had determined a motive, the sheriff said, "It was money."

"We know he knew the family and probably knew about their financial situation and took advantage of them in a desperate time," Hackel told WWJ-AM on Monday. "Marilou is dead as a result of this guy wanting some money."

Johnson, 50, last was seen June 14 at her Washington Township home about 30 miles north of Detroit, where she lived with her boyfriend, Roger Blanchard, and her three sons from a previous relationship. Blanchard reported her missing the following night.

Wright, 37, of Richmond, had gone to the home to give an estimate for plumbing work when, Hackel said, he attacked Johnson in the driveway and cut her throat. Wright then loaded her body into his van, went into the house and stole jewelry belonging to the woman, the sheriff said.

Other people inside the house at the time of the attack apparently did not hear anything. There were no other suspects, Hackel said.

Police knew Wright had gone to the house June 14 and placed him under surveillance shortly after Johnson disappeared, Hackel said. They stopped his van Saturday afternoon in Roseville because it had an improper license plate and found on him a pill bottle containing five diamonds that matched those in a photograph of a necklace worn by Johnson, the sheriff said.

Wright was booked for receiving and concealing stolen property. After interviewing him further, Wright "led us to an area where we think we're going to be able to recover a body," Hackel said.

Blanchard, Johnson's sons and Wright's family cooperated with investigators, he said.

Smith would not release details about the sheriff's department investigation or how it led to Wright. He did say the case came together quickly.

"There are a lot of things that aren't tied together yet," he said.

Johnson's case is the second high-profile slaying that Smith's office is handling this year.

His office also is prosecuting Stephen Grant, who is accused of strangling his wife, Tara, and dismembering her body.

Smith said it is shocking to have two cases of this magnitude come before district court in largely rural Bruce Township.

"This courtroom is known more for agricultural issues," Smith said.

Smith said cases like this can go for weeks to years without being solved, but in the Tara Grant and Johnson slayings arrests were made relatively quickly.