The most expansive search yet and the only one based on specific clues about Gayle McCaffrey’s whereabouts didn’t immediately pan out Thursday as authorities called the investigation especially arduous.

On foot, from the air and with dogs, about 150 people combed 100 acres just east of Drayton Hall along S.C. Highway 61. The private property in West Ashley is a mix of dense woods, gravel pits, ponds and deforested land.

About eight hours of searching in near-90-degree heat revealed no new clues about the 36-year-old mother of two who disappeared on St. Patrick’s Day.

“Any time the investigation goes at length, it’s discouraging,” said Maj. Jim Brady, a spokesman for the Charleston County Sheriff’s Office. “Our main goal from day one has always been to bring Gayle McCaffrey home, to investigate the case and make charges where appropriate. And that’s still our goal.”

The search came a day after McCaffrey’s husband was named as the suspect in a homicide.

Through his attorney, Bob McCaffrey has maintained his innocence and renewed a willingness to speak with detectives so that his wife may be found alive.

The attorney, Chris Lizzi, continued to bemoan what he called a campaign to keep his client in a negative light after weeks of few public developments in the case.

Lizzi again offered his client for questioning. Brady said “we’ll obviously avail ourselves to that opportunity.”

“Personally,” Lizzi said, “I expected this timing to make the story go on. If he is requested to come in for any purpose, my client and myself will cooperate.”

The clue that led a dozen rescue and police agencies from as far away as Summerville to the location was activity on the McCaffreys’ cellphones during or after the time she disappeared, Brady said.

Authorities have said the couple had a disagreement late on March 17, which relatives have said was prompted by a phone call. Authorities said Bob McCaffrey then made an overnight trip Upstate to see a love interest.

He told them he returned the next morning and found his wife’s Jeep, wedding band and cellphone. Gayle McCaffrey was gone.

Sheriff Al Cannon said this week that the farewell note she also supposedly left was bogus.

On two days during the six weeks since her disappearance, agencies have searched a half-dozen areas near the couple’s Limestone Boulevard house. None were prompted by any information gleaned from the investigation, and none revealed anything new.

Gayle McCaffrey’s relatives have resigned themselves to the sheriff’s determination that she is dead. Thursday was the first time authorities have said they are looking for a body.

“We appreciate everything the police are doing,” said one of her sisters, Helen Banach of Summerville. “We just need to find her.”

The searchers split into teams and spread out on the property. They were seen walking side by side, clutching walking sticks and scrutinizing objects they spotted on the ground.

A “scaled-down” group planned to return today, Brady said.

The largest contingent from any one agency consisted of 50 staff members of The Citadel, where McCaffrey worked as the director of facilities finance.

Charlene Gunnells, a spokeswoman for the military college, said McCaffrey was widely liked among her co-workers and was a runner-up for the school’s employee-of-the-year recognition. Family members recently attended a private ceremony in her honor.

Besides The Citadel, the community at large continues to contribute to the search efforts. Brady said Chick-fil-A and Costco have provided food and water.

Reach Andrew Knapp at 937-5414 .