The staples of criminal investigations are well-recognized. Fingerprints. Weapons. Eyewitnesses.
Now detectives are relying on a new tool: cell phones.
Because more than 40% of Americans own mobile phones, law enforcement personnel see them as a powerful resource in investigations and trials. Detectives say phone records, from both suspects and victims, can provide key evidence in murder, robbery, drug and rape cases.
Records of cell phone calls are more useful than those of regular phones because they not only show what numbers were called and when, but also reveal the area where the caller was when the call was made. That allows police and prosecutors to track suspects’ movements--sometimes even while a kidnapping is in progress.
The records also can destroy alibis or attack a suspect’s credibility if his statements contradict the phone data. And murder victims’ phone records can pinpoint when and where they were killed, and connect the victim to the suspect.
“The sooner we get those records, the better,” said Det. Mike Berchem of the Los Angeles Police Department. “They’re invaluable.”
He said he has used cell phone records in every one of his investigations during the last few years, finding suspects, witnesses and accomplices. “It’s hard evidence; it doesn’t lie,” he said.
Cell phone records have proved important in several high-profile cases, including the following:
* Prosecutors used David Westerfield’s cell phone records to track his erratic movements in the days after Danielle van Dam disappeared from her San Diego home. Within 48 hours, Westerfield drove to the desert, the beach and back to the neighborhood where he and the Van Dams lived. He told police he was in the desert scouting for places to take his son camping. Last month, Westerfield was convicted of kidnapping and murdering the 7-year-old girl.
* Alejandro Avila said he was at an Ontario mall when 5-year-old Samantha Runnion was kidnapped from her Orange County condo complex. But authorities said his cell phone records showed that he was near where the girl’s body was found, off a mountain road near Lake Elsinore. Avila is awaiting trial on murder, kidnapping and sexual assault charges.
* The day that LAPD Rampart Division Officer Rafael Perez stole cocaine from an evidence locker, prosecutors said, he made cell phone calls from near where the drugs were stolen, including one call to his drug dealer girlfriend. “It was extremely compelling and significant evidence,” said former prosecutor Richard Rosenthal. Though a jury deadlocked, Perez later pleaded guilty to cocaine theft and was sentenced to five years in state prison.
Cell phones can also be used to connect suspects with their accomplices. Los Angeles County Deputy Dist. Atty. Craig Hum recalled the case of Rebecca Cleland, accused of hiring two cousins to kill her 43-year-old husband, Bruce. Cell phone records showed 11 calls between Cleland and her cousins in the hours leading up to the murder, including one last call 10 minutes before the shooting.
Cleland said a carjacker had knocked her unconscious. But cell phone records placed her cousin Alvaro Quezada about a block from the murder scene, despite his claim that he was at a restaurant 20 miles away. “We could basically prove that he was lying,” Hum said. “Without the cell phone records, it would have been extremely difficult to convict him.”
All three were convicted of first-degree murder in 2000 and sentenced to life terms without parole.
At trial, phone company representatives are called to explain to jurors how the data are collected and what the records mean.
Each cell phone sends a distinct signal. When a call is made, the cell phone signal immediately attaches to the closest cell tower, which transmits the call. As the caller moves into a different area, the cell tower hands off the call to a new tower. Each tower handles an average of 150 calls and reaches a half-mile to two miles in urban areas and up to 50 miles in rural areas, said Jim Righeimer, who owns an Orange County company that leases space for cell towers.
Computers keep data on which tower is being used for calls. If the cell towers are closely spaced, the data can nearly pinpoint where the caller was at the time of the call.
Defense attorneys sometimes challenge the evidence because cell phones can be passed around and often are used by more than one person. Some drug dealers have beat the system by buying cheap phones, using them for one transaction and discarding them.
To obtain phone records in criminal cases, law enforcement must get a search warrant from a judge, who must determine that there is probable cause to believe the target has committed a crime.
The requests put companies in a tough spot, said Michael Altschul, senior vice president of the Cellular Telecommunications and Internet Assn. “They have a legal obligation to be responsive to law enforcement, but on the other hand, there are privacy expectations of their customers,” he said.
As a result, companies will only release records if they have received a court order, Altschul said. But in kidnapping cases, when every second is valuable, companies will make exceptions.
The increased use of cell phone records worries privacy advocates.
“We believe that typical users of cell phones have a reasonable expectation of privacy when it comes to their location,” said David Sobel, general counsel for the nonprofit Electronic Privacy Information Center. “That kind of collection of information is really uniquely invasive.”
Sobel, who studies the privacy implications of new technology, said he also fears that records will be sought more regularly in civil litigation and divorce cases.
LAPD Det. Dennis English said that as more people buy cell phones, the records will become even more important. “They will probably play a greater role in present and future crime scene investigations because of the multitude of cell phones out there,” he said.