After Nhazel Warren was charged with carrying a gun in public this summer, a judge released the 19-year-old on the condition that the Los Angeles County Probation Department track his movements with a GPS device.

When Warren was arrested three weeks later on suspicion of robbing an elderly couple, a different judge released him again with another GPS tracking order.

But although the court doubled down on Warren’s ankle monitor, prosecutors allege he went on to rob two more people in September and October.

Los Angeles Police Department detectives obtained a search warrant against the contractor operating Warren’s GPS monitor in an effort to track his whereabouts. The company was unable to determine his whereabouts at the time of the robbery.

Detectives arrested Warren last week; Court records show this was Warren’s fifth arrest in five months. He pleaded not guilty to charges of fleeing from police, resisting arrest, carrying a concealed weapon in public, assault with a firearm and four counts of robbery. His lawyer declined to comment.

Warren’s case raises questions about how effectively the Probation Department supervises defendants before trial at a time when judges are increasingly turning to GPS tracking as an alternative to prison.

In an emailed statement, probation officials said the department interviewed the defendants and conducted a risk assessment before fitting them with ankle monitors.

According to the statement, in August, the last month for which the Probation Office provides figures, 402 of 1,438 people under GPS monitoring escaped.

The statement also stated that 231 defendants allowed their ankle monitors to run out of batteries, which likely meant they also escaped. Additionally, 142 defendants did not attend appointments with probation officers.

As the public pendulum has swung away from requiring cash bail, probation officials have framed the monitoring program as a fairer way to ensure people show up for court while protecting the public’s safety.

Pretrial release allows people to quit their jobs and care for their families rather than being in jail awaiting trial. GPS devices are often viewed by probation officials, prosecutors and judges as a device that reduces the risk of a defendant escaping or committing a new crime.

In Los Angeles County, the Probation Department’s GPS program was designed to allow law enforcement to track defendants in real time and keep a record of their whereabouts. But records in Warren’s case show that the Parole Department and its contractor, Securus, did not run the program that way.

When detectives obtained a search warrant against Securus, the company did not turn over information from Warren’s GPS monitor, records show. A Securus analyst said the data was so flawed that he would be “uncomfortable” stating it was true.

“To this end, we cannot confirm any data within this time period,” he wrote in a letter to the LAPD.

A spokesman for Securus acknowledged The Times’ inquiry but did not comment. The Probation Department pays Securus about $350,000 a month to operate the GPS system, probation officials said.

Warren had been arrested twice in two months — leading police on a high-speed chase and on suspicion of illegal weapons possession — when LAPD officers stopped him at 55th Street and Denker Boulevard on July 15, according to court records. They searched him and found a gun in his underwear.

According to the petition filed by his lawyer, Warren said he carried the gun because he feared his $20,000 Rolex watch would be stolen.

Warren was released on electronic monitoring by the Probation Department after pleading not guilty to possession of a concealed weapon in public, according to court records.

This was the first time parole officers attached a GPS device to his ankle.

Detectives arrested Warren again three weeks later on suspicion of robbing an elderly couple at gunpoint. Prosecutors allege Warren and 18-year-old Daelan Reed, who was not yet on a GPS tracking system at the time, broke into the couple’s City Center home on July 2.

The 85-year-old female victim, who asked to remain anonymous for fear of retaliation, told The Times that she woke up at 4 a.m. to find two men wearing hooded sweatshirts, masks and gloves in her bedroom.

They told the couple not to move and they wouldn’t get hurt.

He watched as the diamond engagement ring, necklace, bracelet and earrings he received as gifts from his parents and wife were emptied in the jewelry box.

“He even took the pearls my mother gave me,” he said.

She said one of the robbers ordered her 80-year-old husband out of bed, put a gun to his back and demanded cash, a checkbook, a credit card and the couple’s PINs. The couple took the car keys from the kitchen drawer and got into the couple’s BMW and set off.

The woman said that in the days that followed, the thieves withdrew as much money as they could from the couple’s bank accounts.

“What they took away from me, other than the tangible things, is my sense of security,” he said. “My love for my own home. I don’t look at strangers the same way. “It turned me 180 degrees.”

After arresting Warren, detectives searched his mother’s home in Long Beach. They found four handguns and seized $21,000 from the nightstand and $2,583 from Warren’s pocket, her attorney, Geoffrey Ojo, wrote in court documents. Ojo requested the return of $21,000 that she said belonged to Warren’s mother, a “gainfully employed” health care professional who earned $136,859 in 2023.

Warren, who pleaded not guilty to the robbery charges, was released again after paying $150,000 bail. A judge ordered the Probation Department to submit Warren to a second GPS monitoring program and listed the conditions of her release as “no force, violence or weapons.”

Two weeks later, Warren robbed a man who was returning to his Bentley SUV after shopping at Bristol Farms in Woodland Hills, police said. Police said Warren and another man wearing a dark-colored T-shirt and mask knocked the victim to the ground and stole his watch and phone.

A black BMW with stolen license plates was waiting nearby, Det. Emily Delph wrote in a search warrant affidavit. An hour later, the BMW was spotted in the jewelry district of downtown Los Angeles and the suspects were likely trying to sell the stolen watch, Delph wrote.

Detectives found video of the suspects entering a jewelry store. Delph recognized one of them as Warren. He requested a search warrant on Oct. 16 to obtain GPS data from Warren’s two electronic tracking boxes. Delph wrote that historical data will determine whether he was present at the Woodland Hills robbery; Live tracking information will help LAPD find and arrest him.

Neither of them could get it. In a letter, a Securus analyst said the data was so vague that he did not want to swear to its accuracy in court.

“We will never put you in the position of including data in evidence whose accuracy we would be uncomfortable testifying to,” analyst Jeff Marino wrote.

Marino did not respond to requests for comment. His letter did not say why the data was unclear or how widespread the problem was.

Some officials outside Los Angeles County have questioned the reliability of the contractors responsible for monitoring the GPS trackers.

Prosecutors in Louisiana this year charged AEM, a Mississippi-based contractor, with negligent homicide after he shot and killed the wife of a defendant under his control before killing himself in 2021. Prosecutors claim there was a response.

Warren was arraigned on the gun possession case at the Clara Shortridge Foltz Criminal Justice Center in downtown Los Angeles on October 23, where he was given a GPS device for the first time. He pleaded not guilty and was allowed to continue electronic monitoring.

Prosecutors allege that later that day, Warren returned to Woodland Hills. A man was talking on the phone when he noticed a black BMW double parking next to him on Ventura Boulevard around 8:30 p.m.

The man, who asked to remain anonymous out of fear for his safety, told The Times that two men got out of the BMW. He said they wore masks and pointed a gun at his face. When he heard the cocking of the guns, he thought they were going to kill him. “No, no, no, stop!” he shouted.

They wanted him to have the Breitling Navitimer on his wrist. He loved the silver watch with a Stratos gray dial, which was included in 193 of the only 1,000 watches produced. “This was the first expensive watch I ever bought,” he said. “I was working very, very hard.”

He gave the $10,000 watch to the masked men.

Warren was arrested the next day. He and two other men were charged with both robberies in Woodland Hills. Warren pleaded not guilty Monday in a Van Nuys courtroom.

Police could not find the Breitling. The owner was wondering if the robbers would kill someone before being taken to jail.

“Are we really going to wait until we get to that point to do something?” he asked.

The judge set Warren’s bail in the robbery at $150,000.

He posted this and was released, but was still under court-ordered GPS monitoring.