Public safety value has been weighed against privacy issues and deletion schedules are followed, police say.
The video from a few of the city's 200 closed-circuit television cameras showed a flashy Dodge Magnum -- the alleged getaway car in a deadly shooting -- on a big screen for Ramsey County jurors Thursday.
The black-and-silver car with chrome wheels kept circling a block at 6:20 p.m., then stopped as two alleged killers got out by an alley near E. 4th Street and Bates Avenue in St. Paul.
Five gunshots rang out on E. 4th, witnesses said, leaving Dekoda Galtney, 24, shot through the heart and dying as his friends drove him to Regions Hospital on Sept. 28, 2011.
On trial for aiding and abetting the shooting is the alleged driver, Nicholas J. Kruse, 25. He's accused of lying to police and concealing evidence.
His friend, Adrian Flowers, 23, went to prison in June as the shooter in the second-degree murder case. Another shooter hasn't yet been charged.
The use of video from St. Paul's closed-circuit TV (CCTV) during the trial was an example of how police and prosecutors are using the city's newest form of video surveillance, and how much the system's grown.
"There's been more of these cameras that are in the public domain. Then there's a whole host of private security cameras all over; they could be potentially used in the investigation of a case," said Ramsey County Attorney John Choi.
St. Paul Police Sgt. Greg Bakken, who works with the city's closed-circuit camera system, told jurors the 200 cameras are mounted on light poles 20 to 25 feet off the ground. Some zoom and rotate 360 degrees, moving every 20 to 25 seconds. Others are stationary.
Police employees monitor the CCTV from 10 a.m. to 2 a.m. daily, he said.
The CCTV system and similar video surveillance are important investigative tools that can help convict -- or exonerate suspects, said Choi and Howie Padilla, a St. Paul police spokesman.
Padilla said some of the cameras predate the 2008 Republican National Convention, although many were installed downtown for the RNC at the Xcel Energy Center, with the help of federal grants.
More have been installed along University Avenue and elsewhere in the city, and the MTC also uses them.
"There certainly is in my opinion a public safety value. ... What we're trying to do is get to the truth," said Choi, who declined to discuss use of the data in the ongoing trial.
The cameras raise privacy concerns for some.
Choi said public entities, cities and police departments have weighed civil liberties issues carefully. They delete the images according to data-retention schedules, he said.
Bakken and other witnesses testified about images from the cameras, using laser pointers.
Jurors could see kids playing nearby as the alleged killers got out of the car and approached the alley near 4th and Bates.
Earlier, in opening statements, prosecutor Elizabeth Lamin said the killing erupted from "bad blood" between Flowers and Galtney, who had broken off with Flowers' sister. Lamin said Kruse positioned his car for the shooting, then picked up Flowers after and drove him home.
Defense attorney Murad Mohammad said Kruse stayed in the car and did not know what was happening when the shooting was carried out.
Joy Powell 651-925-5038