About a week before Connecticut mom Jennifer Dulos disappeared without a trace last May, two hunters made an ominous discovery on the grounds of a local gun club: a 6-foot-long hole covered with barbecue grill grates.

“One hundred percent a human grave,” one of the Windsor Rod and Gun Club members later told authorities.

The gun club was founded by Kent Mawhinney—a “close, personal friend” of Dulos’ estranged husband, Fotis, who was charged Tuesday with her murder, an arrest warrant states. The court document added authorities now believe the hole was supposed to be a shallow “human grave.”

Mawhinney, a 54-year-old lawyer who previously represented Dulos in a civil lawsuit brought by his mother-in-law, was arrested Tuesday at gunpoint and charged with conspiracy to commit murder in connection with the seven-month investigation into Jennifer Dulos, 50, who disappeared after dropping her children off at school.

Authorities allege Mawhinney repeatedly lied to investigators on behalf of Fotis Dulos, even creating an alibi for the luxury developer, who’s accused of killing his estranged wife at her New Canaan home on May 24.

The lawyer was taken into custody hours after Dulos, 52, and his former girlfriend, Michelle Troconis, 45, were arrested for the third time in relation to the missing mom’s case. Dulos was charged with capital murder, murder, and kidnapping, while Troconis was charged with conspiracy to commit murder.

The two posted bond on Thursday and will be placed under house arrest with GPS monitoring, a Connecticut State Police spokesperson told The Daily Beast.

Although the 50-year-old’s body has not been found, there are “indications that Jennifer Dulos is not alive,” the chief medical examiner’s office said Tuesday.

According to Mawhinney’s arrest affidavit, which was first reported on by the Stamford Advocate, Windsor Rod and Gun Club members told investigators they were out hunting on May 18 when they stumbled upon “an area of disturbed ground.”

“When they looked closer, they uncovered two barbeque grill grates which had been placed over a hole dug into the ground,” the affidavit states. “Small branches and leaves had been placed on the grill grates to hide the pit beneath.”

Inside the 2-foot-wide, 6-foot-long hole, one of the members found a blue tarp and two unopened bags of lime—which he guessed could be used “for trying to get rid of a body,” the warrant states. The two men admitted to investigators that they didn’t think much of their discovery at the time because nobody was reported missing, according to the documents.

On May 24, 2018, six days after the hole was discovered, Dulos vanished. Authorities later found her car abandoned on a New Canaan road “in reverse” with its “lights on,” according to the arrest warrant. Blood spatter was also found on the passenger side of the car.

The warrant states that upon learning about the missing-person investigation, one of the gun club member reported the grave discovery after realizing the close connection between Mawhinney, the club, and Fotis Dulos.

“Mawhinney was responsible for the club’s existence,” the warrant states, noting that while the attorney had left the club a year prior, he had recently expressed interest in rejoining in March or April and was given a key to the property. “He had found the land and helped to secure it and establish the club 12-15 years earlier.”

But by the time the gun-club member told police about the hole in June, it had been filled and covered “as neat as a pin.” A search of the area did not reveal any human remains, police said.

Investigators eventually interviewed Mawhinney on two separate occasions, and he allegedly lied on behalf of his friend several times.

In one interview, Mawhinney claimed he didn’t see or hear from Fotis Dulos the day Jennifer went missing, even though Troconis told police she saw the attorney in his house, the warrant states.

“I don’t remember having contact with him. If there’s a phone call I guess I did but I don’t remember having contact with Fotis,” Mawhinney told investigators.

Phone records indicated the two spoke for an hour the day Jennifer Dulos went missing. When investigators confronted him, Mawhinney continued to deny having had any contact with his friend—alleging he had suffered a “concussion” on May 25 and had to replace his cellphone as a result of the fall, the warrant states.

During the same time period, Dulos and Troconis dumped several black garbage bags in Hartford that contained items stained with the missing mother’s blood, including a shirt, mops, gloves, a sponge, a bike, and zip ties, according to video surveillance.

This is not the first time Mawhinney has been criminally charged. In August, he was charged with sexual assault in a spousal or cohabiting relationship, second-degree unlawful restraint, and disorderly conduct, after his estranged wife accused him of assault and violating a protective order after the two agreed to divorce. Those charges are still pending.

The same woman also alleged that Fotis Dulos tried to lure her to his home on May 16—about a week before his own wife vanished— and “had stated that Mawhinney told her he wanted [her] back and that he loved her.” She didn’t agree to the meeting, however, because she felt the meeting was a ploy “to get rid of her,” according to court documents.

“She reported that she believed it was suspicious that Dulos had such a sudden vested interest in her relationship with Mawhinney,” an arrest warrant states. “She stated that she felt she was being ‘baited’ and was uncomfortable with the fact that Dulos kept inviting her back to his residence.”