Attorney prepares 'alibi defense' for estranged husband of missing Connecticut mom Jennifer Dulos, 50, was last seen on May 24, according to New Canaan police.

Fotis Dulos, the estranged husband of missing Connecticut mom Jennifer Dulos, has insisted he didn't kill his wife and doesn't know where her body could be, his attorney said.

"This is a troubled couple going through troubled times," Norm Pattis, Fotis Dulos' attorney, told ABC News on Tuesday. "I simply don't know [where Jennifer Dulos is] and he doesn't know either."

"There are troubling questions or good reason for the police to search and conduct their inquiry [into her disappearance]. I'm not disputing that," Pattis said. "We are anxious to meet those accusations and clear his name."

Fotis Dulos and his live-in girlfriend, Michelle Troconis, are charged with tampering with or fabricating physical evidence and hindering prosecution in the mysterious disappearance case.

Both pleaded not guilty on Tuesday.

More charges are likely, prosecutors said last week.

Jennifer Dulos, who had five children with Fotis Dulos, vanished last month amid a contentious custody battle with her estranged husband.

She was last seen on May 24, police said. Investigators believe she suffered a "serious physical assault" in the garage at her New Canaan home, where bloodstains were found, according to arrest warrants.

Clothes and sponges with Jennifer Dulos' blood were found in trash cans in Hartford, where surveillance cameras captured a man appearing to be Fotis Dulos disposing of garbage bags, according to the documents. A woman in the passenger seat of the man's car fit the appearance of Troconis, according to the documents.

Pattis said he can't account for the surveillance footage or the bags in the dumpster.

But based on the timeline of the day Jennifer Dulos went missing, "it seems to be implausible" that Fotis Dulos could have killed her, his attorney said.

That morning, Fotis Dulos met with a lawyer at his home in Farmington, Connecticut, until about 9 a.m., according to Pattis. The attorney believes Fotis Dulos' phone and computer records will prove he was home through the morning when Troconis returned around 11 a.m.

"There is no dispute between Mr. Dulos and the state that he was back in Farmington by 1:33 [p.m.]," Pattis said. "So to our minds that is an effective alibi. Because in order for him to have accomplished this crime, Ms. Dulos dropped the kids off at school at about 8:30 [a.m.]. The housekeeper was back in the house by about noon and didn't notice anything amiss. Apparently hadn't gone into the garage."

Pattis said that leaves a few hour window where his client would have had to drive the 70 miles from his home in Farmington to his estranged wife's house in New Canaan, where "he would have had to confront Ms. Dulos in the garage or some other part of the house, kill her, try to clean up, dispose of the body in broad daylight on a well populated section of the state and get back to Farmington."

"If the electronic data confirms that his devices were in use at that location, it’ll be an open question whether he was using [the devices] or someone else was. But from where I come from, this is the beginning of an effective alibi defense," Pattis said.

"The alibi is enormous," the attorney added.

In court on Tuesday, prosecutors said Fotis Dulos' DNA was found mixed with Jennifer Dulos' blood on a faucet in her kitchen.

But the defense says it's not unusual that his DNA was there as Fotis Dulos had been at his estranged wife's home several days before she went missing.

Fotis Dulos "had dinner with the kids, played basketball with them," Pattis said. "Did he go into wash his hands? Did he touch something else? Was there transfer DNA? I don't know."

Fotis Dulos posted bond on Tuesday and was outfitted with a GPS. His next court date is scheduled for Aug. 2.

Troconis, who is also out on bond, is due to return to court on July 18.

ABC News' Katherine Carroll and Carlos Boettcher contributed to this report.