Late on the morning of April 14, 2006, a troubling letter rolled off the fax machine in the harried, disordered fingerprint unit of the Los Angeles Police Department.
Months before, one of the unit's print specialists had determined that several prints lifted from a cellphone store where a burglary had occurred belonged to Maria Maldonado, a 25-year-old hospital technician. Two others in the unit had signed off on the work. The match had given authorities the evidence they needed to arrest the woman and charge her with the crime. When the case went before a judge, however, a renowned fingerprint expert testified that the police had made a mistake.
The district attorney's office sent the fax demanding answers.
The analysts stood by their work, but days later the file containing the suspected burglar's prints mysteriously disappeared from the unlocked drawer where it was kept. Working from copies of the prints, others in the unit and outside consultants later concluded that Maldonado had, in fact, been wrongly accused, and the charges were dropped.
The case offers a stark profile of a high-stakes operation that for years has been marred by inadequate training, antiquated facilities, poor supervision, careless handling of evidence and other shortfalls, according to internal police records and interviews.
"We were trying to hold on by the skin of our teeth to make sure things were done right," said Diana Castro, the latent print unit supervisor who retired early last year. "Were we perfect? No. Did we do everything right? No. We did what we could to keep the cases flowing -- to assist the detectives and the community."
As focus in law enforcement has turned increasingly to the promise of DNA analysis to solve crimes, the fingerprint unit has languished as a neglected but heavily used cornerstone of the LAPD. It operates 24 hours a day, seven days a week, with about 80 forensic print specialists rotating through three shifts.
They are summoned by detectives to roughly 24,000 crime scenes every year and about 60% of the time are able to collect fingerprints.
Prints are scanned into automated databases that generate dozens of possible matches to known people. Specialists then seek a more precise match by comparing the prints under a magnifying glass, looking at the distinct ways in which the ridges of skin that make up a fingerprint split, stop and loop. Conclusive matches are made about 3,500 times a year.
The unit has long struggled to stay on top of its workload, and work often backs up. Currently, fingerprints from 3,018 property crime cases need to be entered into the computer database, and 1,052 cases are awaiting a more exacting manual analysis. The unit has not tended to requests from detectives trying to solve 320 homicides and other cold cases, according to department figures provided to The Times.
In the wake of the Maldonado case, senior LAPD officials made some improvements to the unit but failed to address many other serious shortcomings.
After The Times reported last month on an internal LAPD report that highlighted many of the ongoing problems in the unit, officials tightened the procedure for verifying fingerprint matches and, more recently, have reassigned several print specialists involved in misidentifying Maldonado and a woman in another case, pending an investigation of their work.
Even with these changes, however, much still needs to be done to improve the efficiency and ensure the accuracy of the unit's work, said LAPD Deputy Chief Charlie Beck, who heads a recently formed task force investigating the fingerprint unit.
"It is a place that has been overlooked and pushed into a corner," he said. "That has to change."
The unit's facilities offer perhaps the most obvious indication of the priority the unit is afforded. As DNA work is conducted in a newly built laboratory, fingerprint comparisons are done in a converted kitchen on the eighth floor of the department's downtown headquarters.
The unit's automated database work is done four flights below in a space shared with the unit's administrators. Fingerprint files are stored elsewhere. With too little room to have their own work space, three specialists are assigned to each desk.
Beck, Castro and others described a chaotic, disruptive atmosphere in which print specialists must often break their concentration to answer constantly ringing phones.
Long-standing plans to relocate the unit were scrapped in order to expand DNA lab facilities. The department and city agencies are searching for an alternative site for the print unit, Beck said.
That a file containing original fingerprints in the Maldonado case could vanish illustrates serious flaws in how evidence has been handled for years.
Specialists have been warned repeatedly for years to be more diligent when signing prints in and out of the unlocked filing cabinets where case evidence is stored, according to internal records obtained by The Times.