Dateline: Down the Basement Stairs – 5 harrowing details about Annamarie Cochrane Rintala’s murder, explored

Annamarie Rintala's murder in 2010 fueled one of the most publicly visible criminal trials in Massachusetts. Dateline: Secrets Uncovered's "Down the Basement Stairs" in May 2025 covers the complex case and subsequent trials. The series provides a timeline of the crime, the following legal complexities, and the forensic ambiguities that dominated the case. The show also highlights the wider legal significance of the trial: Cara Rintala was the first woman ever to be charged with murdering her legally married wife in the state.

On the late night of March 29, 2010, a 911 call was placed to paramedics in Granby, Massachusetts. Annamarie Cochrane Rintala, a paramedic, was found at the bottom of her basement stairs dead. Cara Rintala, her wife, placed the 911 call. The crime scene was full of questions from the start.

Dateline explores those questions and distills five significant points that guided the investigation and prosecution that lasted for years.

Here are 5 harrowing details about Annamarie Cochrane Rintala’s murder

1. The basement scene: Paint, blood, and a pillow

Dateline: Secrets Uncovered discovered Annamari in the basement of her home with Cara. She had blood and white, latex-based paint on her, and two pillows over her head. There were no signs of break-in or burglary that the first responders noticed at the time.

Cara informed the authorities that she had spent time with their daughter and returned home to see Annamarie at the foot of the stairs. The scenario, however, was suspicious. Paint not only covered Annamarie's body but also some drops below her shoulders and head. The situation called for a more intense forensic investigation that would be critical to subsequent trials.

2. History of violent relationship with an extensive pattern of abuse

Dateline said the two had a long history of several years of household battles. Frequent police calls throughout the years were noted on police reports. Cara and Annamarie had, at some point, both posted restraining orders against the other, and both had been charged with violence.

Witnesses interviewed during the investigation testified that the relationship was emotionally volatile and sometimes physically violent. Friends, family members, and coworkers testified to heightened fears of escalating tensions. These events were utilized in the prosecution's case on the history of behavior and motive.

3. Cause of death: Manual strangulation was established, but the chronology remained unclear

The autopsy determined that Annamarie died from manual strangulation and the presence of extreme head trauma disguised in the form of laceration and contusion. The finding provided the cause of death, but forensic evidence left everyone speculating about it in terms of the case.

Such a test one of them was, since as Dateline says, how precisely to determine the time Annamarie died, and if any injuries could have resulted from falling. The defense leaned on the vagueness of the injury and the absence of direct evidence against Cara for the crime.

Prosecutors countered with the totality of circumstances—blood spatter, cellular data, and condition of the crime scene—to make their explanation of a violent fight followed by the staging of the crime scene credible.

4. Four trials, one overturned conviction, and years of legal uncertainty

Cara Rintala was charged in 2011, more than a year following the beating. Her initial two trials in 2013 and 2014 both ended in hung juries. She was convicted in 2016 of first-degree murder. But as Dateline relates, the conviction was later reversed in 2021 by the Massachusetts Supreme Judicial Court.

The court again asserted that the evidence of the latex paint—to serve as evidence to corroborate the theory that the crime scene had been staged—was scientifically flawed. Specifically, the test of the paint's drying time conducted by the expert witness was held to be inadmissible. This reversal created a fourth trial and reignited controversy surrounding the application of forensic science in legal proceedings.

5. Last trial outcome

A voluntary manslaughter conviction had previously occurred. Cara Rintala was found guilty of voluntary manslaughter instead of murder in her fourth trial, which concluded in October 2023. She was given credit for time served and sentenced to 12 to 14 years. Although the conviction was on a lesser charge than what the prosecutors originally requested, it brought an end to a long legal struggle.

Dateline made clear that the voluntary manslaughter conviction meant the jurors agreed there was evidence of a fight that was fatal, but were not satisfied the act was premeditated murder. The defense still maintained there was no concrete evidence to incriminate Cara in the murder and referred to the absence of witnesses, weapon, or forensic certainty.

Dateline: Secrets Uncovered presents an inside, information-packed view of the Annamarie Cochrane Rintala case. It offers up the forensic, personal, and legal complications that made this case difficult to prosecute and difficult to ignore.

From cross-adversarial expert witnesses to jury verdict flipping, the episode introduces viewers to a system of justice struggling with one of its most complex and sensationalized trials.