BOULDER, Colo. -- Two suspects in the slaying of a Lafayette woman have been ordered to provide DNA samples and fingerprints to investigators so they can determine who wrote a good-bye letter to the woman and a "to-do list" of things to do after the slaying.

A Boulder judge ordered the victim's teenager daughter and boyfriend to provide the forensic evidence, according to a report in the Boulder Daily Camera.

The decomposing body of Linda Damm, 52, was found in the back of her Subaru, parking in the garage of her Lafayette home on Feb. 28. Her daughter, Tess Damm, 15, and daughter's boyfriend, Bryan Grove, 17, were arrested in connection with the case, in addition to two other teenagers.

According to police, Grove stabbed Linda Damm to death several weeks earlier after planning the slaying with Tess Damm.

The Colorado Bureau of Investigation has a "letter to Mom" that was found during a police search of the home after the discovery of Damm's body, according to the news report. Police have not revealed what the letter says.

According to court records, a "to-do list" was also found in the Damm home, but police wouldn't elaborate on what it said.

Investigators are trying to determine who wrote each document.

Tess Damm had told friends and police that her mother was an alcoholic who abused her. She is charged as an adult with conspiring to kill her mother. Grove is charged as an adult with first-degree murder the in case.

A preliminary hearing for the two has been scheduled for May 21.

A third teen, Jared Guy, 18, is charged with being an accessory after the crime and tampering with evidence. He is scheduled to enter a plea in the case next week.

Jared Smith, 16, entered a guilty plea in March to a juvenile charge of accessory and was sentenced to two years in juvenile prison.