AI is reshaping police detective work, starting with cold cases

• AI's first wave in policing was about the streets: drones, license plate readers, gunshot detection and tools that promise faster response and more "eyes" on the city.
• Now comes the second wave: AI for detective work that involves combing through jail calls, interviews, social media "warrant returns," photos and old case files to surface relevant moments faster.

Zoom in: AI startups Closure and Longeye are two firms offering law enforcement agencies new tools to search mountains of evidence often overlooked by overworked detectives and forensic investigators.

• The Anchorage Police Department in Alaska adopted the Closure tool after a test period, with the Anchorage Assembly approving a five-year, $375,000 contract.
• The Redmond Police Department in Washington State and the Wyomissing Police Department in Pennsylvania are now using the Longeye AI tool to accelerate cold case and active case investigations.
• The agencies say the tools have allowed investigations to process hours of recorded messages and interviews in a matter of minutes — and helped advance cases.

How it works: Investigators upload or pull in large datasets, such as jail calls, interviews, and photos, into a single workspace so they can be searched as a single corpus.

• The systems transcribe audio, label images and highlight crucial text messages so detectives can move from hours of listening and reading to quick searches and retrievals.
• The AI software can analyze evidence across many foreign and Indigenous languages and translate so that monolingual investigators can search for clues and confessions.

What they're saying: "There are cases that get screened out because we just don't have the capacity to deal with them," Anchorage Police Chief Sean Case tells Axios.

• Case said AI is helping Anchorage restart cold case and missing-person investigations of Alaska Natives by allowing new detectives to ingest entire case files — including decades-old documents and scanned records.
• "It gets (investigators) up to speed on that case file in a matter of hours versus a matter of weeks."

Closure CEO Aaron Zelinger tells Axios the AI tools aren't meant to automate decisions, but to surface relevant material for humans to verify.

• "It's creating a bunch of 'Watsons' to help Sherlock Holmeses," said Zelinger, a former Palantir engineer.

State of play: A Cellebrite trends survey last year found nearly 70% of investigators say they don't have enough time to review all the digital data in their cases.

• That's putting pressure on all departments, not just small, short-staffed ones, to look at AI to assist with cases.

The other side: The American Civil Liberties Union (ACLU) warns that using AI in core criminal justice documents and processes raises "significant civil liberties and civil rights concerns," including risks tied to bias and reliability.

• The Electronic Frontier Foundation said it's also difficult for the public even to determine whether agencies are using AI systems, and how that uncertainty complicates accountability and records requests.

Yes, but: Zelinger argues that AI must make investigations more transparent, not less, by requiring users to return to the original evidence every time.

• He said all evidence still has to go under cross-examination and court scrutiny.
• "We do not want AI automating law enforcement decisions."

The intrigue: Closure can even offer detectives alternative theories and suspects after the tool has examined all the evidence.

• Case said the process helps detectives "tighten up loose ends" before trial, reducing surprises in court.
• There's also AI for defense attorneys: JusticeText, a company founded by two University of Chicago undergraduates, has developed technology that uses generative AI to help overworked public defenders and defense attorneys quickly navigate police body cam footage.

The bottom line: The more police rely on AI to navigate evidence, the more due process hinges on transparency about how those tools work.