The NYPD officer who killed her one-year-old son and her boyfriend before killing herself yesterday morning was allegedly arguing with her boyfriend about a note she received concerning their relationship. The Wall Street Journal reports that 43-year-old Rosette Samuel began arguing with 33-year-old Dason Peters on Saturday "over a hand written letter" that was later torn up and flushed down the toilet. On Monday morning, Samuel would kill Peters and her son, Dylan Samuel-Peters, in their East Flatbush home, before turning the gun on herself.

Investigators told reporters that the contents of the note were unknown.

Samuel's older son from a different relationship, 19-year-old Dondre Samuel, said he woke up yesterday morning and "saw his mother standing with a gun as Peters sat on the floor." He was then ordered back into his room by the couple when he heard a gunshot. The teenager called 911 and scrambled out of his bedroom window to meet police.

At some point before any shots were fired, Dondre Samuel said his mother apologized to him, and told him that she left a note for him. Police say that note stated that she was sorry for her actions and that the $42,000 she had in a retirement account was to be used so that Dondre could attend college.

Peters, a track maintenance supervisor for the MTA, was scheduled to travel to his native Guyana on Monday. An unnamed relative told the Daily News said that the trip was just a vacation. "He wasn't going to live there. He has a good job. He was just going for a week or two."

Samuel, a police officer since 2000, had recently been transferred from the Manhattan Traffic Division to the 108th Precinct, which covers Long Island City and Sunnyside, at a salary of $97,064 with overtime. While the Daily News describes her as a "loner," and quotes "one cop" as saying that Samuel "didn't have any friends," another officer from Manhattan Transit told the Post, "We're devastated right now."

The officer adds, "She was a lovely person. She was funny, a great personality, outgoing. She'd always talk about her family…She was very fond of her children. They were her life."