Husband-Wife Love Triangle Cited in Double Homicide

— -- An alleged love triangle that resulted in two deaths has led to the arrest of a Maryland mother, her daughter and her daughter's boyfriend, who police say teamed up to kill her husband and another woman living in the basement of the family home.

The slain woman had a romantic history with both the accused mom and her deceased husband, police said.

Anne Arundel County Police have unraveled the alleged plot that they say involved a fake suicide report, missing murder weapons and an apparent effort to have the victim's daughter take the "fall" for her boyfriend.

The deaths were first reported Monday Oct. 5 when Ann Marie Anastasi called police to report that her husband, Anthony Anastasi Jr., had killed himself in their house, officials said.

She told investigators that she could hear him arguing with Jacquelyn Riggs, the 25-year-old woman who lived in their basement, the night before, according to her charging document.

When he came back up to the bedroom that he shared with his wife, he told her "to get the kittens and for her to get out of their bedroom," before he locked the doors, she told police said.

Ann Anastasi told police that she didn't realize her husband was dead until the next morning. "When she returned home from the grocery store she tried to wake Anastasi Jr. for a doctor appointment," the police charging document states.

She told investigators that she then saw a gun lying next to him in the bed and she called police.

Police say they later determined, however, that the gun lying next to Anastasi was not the same make or caliber as the bullet that had been used to shoot him in the chest. They also "found gunshot residue on Ann Anastasi's person and clothing," the police report states.

Police also found Riggs stabbed to death in the basement. Both her and Anastasi's deaths have been ruled homicides. Police have not recovered either of the weapons. Nor have they said who allegedly killed whom.

It was only when Ann Anastasi and her 13-year-old daughter were brought in for questioning at the police station that the troubled state of their marriage came to light, including that both Ann and Anthony Anastasi had had romantic relationships with Riggs before her death, police said.

"It was determined the marriage between Ann Anastasi and Anastasi Jr. was fraught with conflict and domestic abuse. Historically Ann Anastasi, Riggs and Anastasi Jr. were all sexual-romantic partners," the charging document states.

Police went on to describe the marriage as "strained" but noted that Riggs, who had moved into the family's basement this summer, was still having a romantic relationship with Anastasi Jr. but no longer with Ann Anastasi.

When police looked over Ann Anastasi's cell phone records from the night of Oct. 4 into the morning of Oct. 5, they discovered that "there was communication with another phone/individual conspiring between the above defendant [Ann Anastasi] and juvenile [her 13-year-old daughter]," according to the charging document.

ABC News is not releasing the name of the daughter because of her age.

The text messages mentioned the "murder of two individuals" as well as details like the "exchange of a handgun" and transportation to the crime scene, according to Ann Anastasi's charging document.

Police say they were able to determine that the other person involved in the text exchanges was Gabriel Ezekial Struss, the 18-year-old boyfriend of the 13-year-old daughter.

Ann Anastasi picked him up on the night of the slayings and took him to her home, according to Struss' charging documents.

Police say they were also able to determine that the 13-year-old had been texting Struss about how she would be "taking the 'fall' or blame for the murders," his charging documents state.

Ann Anastasi was taken into custody Thursday and charged with two counts of first- and second-degree murder, as well as use of a firearm in the commission of a felony. She is being held without bond.

The daughter was also taken into custody and charged with two counts of first-degree murder and accessory after the fact. She was put in juvenile detention.

Struss was arrested this morning and charged with two counts of first- and second-degree murder, two counts of conspiracy to commit first- and second-degree murder, and two counts of firearm use in a felony crime of violence.

ABC News' Josh Margolin contributed to this report.