Michael McNew seemed to be reeling last Aug. 6, arguing for hours with his girlfriend, alternating between threats of violence and declarations of love.

"I wanted you to be with me forever. You chose not to. I can't compete with your love," he wrote in one of a long series of text messages to Jennifer Morrissey. "You have a new boyfriend now. … I have always loved you beyond your imagination and mine, but you chose differently. And I guess 4 years with you is all a waste of my time."

About three hours later, McNew, 64, was dead, shot once in the face inside the home in Washington Crossing that he once shared with Morrissey.

The slaying of McNew – a district sales manager for pharmaceutical giant AbbVie – drew headlines across the region. That attention spiked a month later, when Morrissey, 31 years his junior, was charged with his murder.

As Bucks County prosecutors prepare for Morrissey's trial, tentatively scheduled for September, they've filed a new motion that provides insight into the bleak ending of the couple's relationship.

Investigators have described the older man as Morrissey's "sugar daddy," whom she met while working as an exotic dancer. But S. Philip Steinberg, Morrissey's attorney, cast doubt on the characterization, saying the prosecution's evidence, much of it from confidential informants, came from "tainted sources."

"She's ultimately someone that suffered a lifetime of abuse, and continued to be in an abusive and inappropriate relationship with the decedent," Steinberg said. "He met a struggling girl and bought her things as a means of control, not of love.  He was someone who was a man of means, and he held it over her head throughout their relationship."

Steinberg said he planned on filing a response to the motion Wednesday.

In the prosecution's motion, filed July 2, Deputy District Attorney Christopher W. Rees pushes for access to a smartphone owned by Morrissey that police seized but have been unable to access due to a "swipe code." If investigators unsuccessfully try to unlock the phone too many times, it could delete its contents, Rees wrote in the motion.

Officials were tipped off to the second phone's existence by a text message between Morrissey and Charles "Ruthless" Kulow, the boyfriend alluded to in the conversation with McNew. Morrissey sent Kulow a message on Aug. 24 advising him to "text my other phone," and a confidential informant told investigators she bought the second phone after McNew's slaying, since he had been paying for the one that police have been able to access, according to court paperwork.

And that first phone has proven essential in building the case.

It revealed the final conversation between the two in great detail, a bitter argument over what appears to be a love triangle of sorts among McNew, Morrissey and Kulow, a member of the Breeds motorcycle gang with a criminal record that includes convictions for robbery, assault and drug offenses.

Kulow, locked up since January in Philadelphia's Curran-Fromhold Correctional Facility, is awaiting a murder trial of his own: He is accused of killing Brian Jones, 40, in November 2016 during an argument and dragging his body onto a sidewalk in the city's Holmesburg section, according to investigators.

McNew accused Morrissey of not caring about him anymore — of favoring Kulow, according to the texts from her seized smartphone, which she had deleted.

Morrissey responded by saying that if McNew kept complaining, he wouldn't "have to worry about leukemia killing you, because I will put you in the [expletive] ground myself."

McNew said that "well maybe that's better," and Morrissey quipped that "it would be a lot quicker."

The argument continued for the better part of two hours, with McNew first begging Morrissey to come back and then telling her she was no longer welcome in his home. He promised to move her belongings into a storage locker for which he had prepaid two months' rent.

She warned him not to touch her possessions, threatening to "gut you like I'm field dressing" a deer. He responded with threats of his own, calling her "unappreciative" and saying he would shoot her if she came to his home.

The venom being spewed seemed to contrast with the support McNew previously gave Morrissey, who prosecutors say worked as a motorcycle mechanic.

McNew posted bail for Morrissey in a 2014 drug case, and paid more than $4,000 in "financial court obligations" stemming from violating her probation from that arrest, court documents show. He paid almost $2,000 in a separate case two years later, when Morrissey struck a bicyclist while driving McNew's car.

She was also the beneficiary of "at least two" of McNew's insurance policies.

But their relationship apparently soured. McNew's son told police at the time of Morrissey's arrest that he had seen the couple arguing during a visit to their home the week before his father's death, according to a criminal affidavit.

Investigators believe  Morrissey came to McNew's home about 9:30 on the night of his death, based on data from cellphone towers near the victim's home. What exactly happened when she arrived remains unclear.

Morrissey herself, when first questioned by police, tearfully warned investigators that McNew had to "fear for his life" from Kulow, according to police paperwork. At the time of the questioning, she was in custody for violating her probation in an unrelated incident.

A jailhouse informant locked up with Morrissey told police that she talked of killing McNew in self-defense, according to an affidavit filed in her arrest. Morrissey went to confront McNew over the threats he had been texting her, the informant said, and when she arrived he brandished a gun at her.

After Morrissey wrestled the gun away from McNew, it accidentally went off and killed him, according to the informant's account.

Other informants told police that Morrissey said she returned to the house after the shooting to stage a burglary, taking a phone and laptop with her. She allegedly told the informant that she worried her "phone and smart-watch" would place her at the scene of the killing.

Steinberg, Morrissey's attorney, has criticized the informants' information, calling it circumstantial. He criticized prosecutors for using information given by sources offered "benefits for cooperating."

"What is 100 percent from all of the evidence, from every source, is that she came to the house to retrieve her belongings, a place where during the course of a day she's invited to come back to, begged to come back to, and told that she's loved," Steinburg said. "And she's met with Mr. McNew, who is brandishing his own weapon. But the facts of what happened when she is met by him, that will all come out at trial."