But police have not found the weapon or the killer's bloody clothes. The culprit left no fingerprints, and there were no witnesses to the crime.
"It is guesswork. It is supposition," said one of Robb's lawyers, Robert J. Levant. ". . . It's fairy tale."
Robb, 56, a tenured economics professor, has denied any role in the crime. He told police that he had arrived at his house, on Forest Road, in the early afternoon to find his wife dead in what he suggested was a bungled burglary. Glass in a rear door was newly broken, he said.
Montgomery County Prosecutor Bruce L. Castor Jr. dismissed the burglary scenario. He noted that no one had stepped on the broken glass scattered on the floor, and he suggested that the break-in had been staged.
When investigators searched the house, they noticed a tool missing from a line of implements hanging on a garage wall. Ellen Robb's brother, Arthur Gregory, testified that he had seen a crowbar there when he helped his sister clean the garage a few years ago.
Accompanied by police, Gregory went to Home Depot and found a similar crowbar. A medical examiner later concluded that such an object could have been the weapon, Castor said.
Levant cast doubt on Gregory's recollection by questioning him about other tools he had seen on the wall, then producing a photograph to prove him wrong.
Prosecutors contend that Robb killed his wife in a rage over her plans to leave him and sue for custody of their 12-year-old daughter, Olivia, along with half his assets.
A divorce lawyer testified that Ellen Robb had recently consulted him, but he acknowledged under cross-examination that she had talked about divorce many times over the years.
The lawyer, Albert Shemtob, also said Ellen Robb had "mental-health issues." Levant asked him to elaborate, but Castor objected, and the judge would not allow him to answer.
Throughout the hearing, Robb, who sported a new goatee and wore a pale lavender shirt, jeans and sneakers, took notes on a legal pad and offered periodic suggestions to his three lawyers.
After more than three hours of testimony, District Justice William I. Maruszczak ruled that there was sufficient evidence to proceed to trial.
As he left the building, Gregory said he felt "a mix of emotions" about testifying against his brother-in-law. "It's very hard to look at him directly," he said.
Contact staff writer Nancy Phillips at 215-854-2254 or firstname.lastname@example.org.