LOS ANGELES — Los Angeles police are increasingly relying on technology that not only tells patrol officers where crime is most likely to occur but also identifies and keeps track of ex-cons and other bad guys they believe are most likely to commit them.

Police say the effort has already helped reduce crime in one of the city’s most notorious and historically gang-ridden neighborhoods.

“This is a tremendous step forward. Without this, I couldn’t do my job,” said Capt. Ed Prokop, head of the Los Angeles Police Department division that watches over the grimly nicknamed “Shootin’ Newton” area.

The program — part data collection, part lightning-fast computer platform, part street-level intelligence-gathering — is expanding in LA with the help of a recent federal infusion of $400,000 and has drawn interest from departments across North America.

Dubbed LASER for its ability to zero in on offenders and hotspots, it is one of many newer law enforcement tools that use data tracking and collection — such as license plate scanners and cellphone trackers — often with little public knowledge or regulation.

Privacy advocates say LASER isn’t transparent, has no clear oversight and unjustly focuses on keeping ex-convicts under suspicion even though they’ve served their time.

“People who have paid their debts to society shouldn’t remain stigmatized in the eyes of police,” said Kade Crockford of the American Civil Liberties Union.

LASER uses technology developed by the CIA’s venture capital arm to realize a post-9/11 dream that allows investigators to match up vast troves of data from 15 separate sources to connect dots that they otherwise might miss.

Funded by federal grants, it launched in 2011 and an expansion funded by additional money in October brought the program to a total of eight areas throughout the city.

More than 3,500 LAPD officers have been trained to use Palantir, a platform that was introduced initially to speed up the process of creating dossiers on chronic offenders and is now used throughout the department for a variety of investigative purposes.

Officials from New York, Nevada, Wisconsin, Washington, Texas and Canada have been briefed on LASER, said Craig Uchida, president of Justice & Security Strategies and the program’s research partner.

There has been little outside scrutiny of LASER because the nearly $1 million used to fund it doesn’t affect city budgets. Police officials, however, say it works and cite a steady drop in killings in Newton compared to other areas not using the program.

There were 39 homicides a year before the program started and 14 last year, they say. And at the end of the first year, 87 of the 124 people identified as chronic offenders were arrested at least once for “like crimes,” officials said.