A more than decade-old sexual assault case in Acton ends with a 15-year prison sentence for a Lunenburg man

ACTON – After more than a decade, justice has finally been served for the victim of a brutal sexual assault in Acton.

Authorities announced Tuesday that the cold case reached its conclusion this month when a Middlesex Superior Court judge sentenced Christopher Aldrich, 30, of Lunenburg, to 15 years in prison for sexually assaulting a 22-year-old woman in June 2013 had raped her with a knife.

“I hope that knowing the perpetrator will be held accountable for this heinous crime provides some relief to the survivor,” said Acton Police Chief James Cogan.

The crime occurred on the evening of June 18, 2013. According to authorities, the woman was waiting alone at the South Acton Commuter Rail Station, talking on the phone, when a stranger approached her. After she ended the conversation, the man brandished a knife, threatened her and raped her at knife point. He then fled the scene on foot.

After the attacker fled, the victim called the police, who arrived within minutes. Despite a thorough search, police were unable to locate the suspect. Authorities noted that there were no surveillance cameras in the area.

The victim was taken to a nearby hospital where a trained sexual assault nurse treated her. Forensic evidence collected during the investigation was sent to the state police crime lab, where chemists created a detailed DNA profile of the attacker. However, comparisons with state and national offender databases revealed no matches.

For more than eight years, the perpetrator remained unknown despite sustained investigative efforts by Acton police and the MBTA Transit Police.

The case gained traction in 2021 when prosecutors and law enforcement hired Virginia-based Parabon NanoLabs to conduct forensic genetic genealogy analysis. This advanced technology analyzes DNA profiles to identify distant relatives of the source, helping to build a pool of potential suspects. Through those efforts, Aldrich was identified as a person of interest, according to authorities.

On November 9, 2022, Aldrich was involved in a single-car collision when his Ford Crown Victoria struck a utility pole on School Street in Acton. Police responded, conducted an on-scene investigation and lawfully seized several items from Aldrich’s vehicle, including an open bottle of Fireball whiskey.

Crime lab employees wiped the neck of the whiskey bottle and used it to create a male profile. This profile matched the perpetrator profile of the 2013 sexual assault victim.

Authorities determined that the expected frequency of this profile in the population was approximately 1 in 3.161 sextillion people, or 1 in 3,161,000,000,000,000,000,000.

Authorities obtained a court order from Middlesex Superior Court requiring Aldrich to undergo a buccal swab, in which a trained officer uses a cotton swab to collect cells from the lining of the mouth. The swab was then sent to the state police crime lab for analysis and compared to DNA from the 2013 attack. Chemists confirmed that the DNA collected from Aldrich matched the perpetrator’s profile, with an estimated frequency of about 1 in 11.94 sextillion people.

Aldrich was subsequently arrested in February 2023. This month he pleaded guilty to aggravated rape in Middlesex Superior Court and was sentenced to 15 years in prison by Judge Catherine Ham.

“After more than a decade, Christopher Aldrich has finally been held accountable for this attack after evading justice for so long,” said Middlesex District Attorney Marian Ryan. “This case is an example of how good investigative work combined with new technology can not only identify suspects, but also bring these cases to a solution.” Our Cold Case Unit is at the cutting edge of innovation and is making real progress despite the passage of time in solving cases. Aldrich’s conviction demonstrates that this work is effective in actually bringing defendants into the courtroom and providing victims with the answers they have been seeking for years.”

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