For years, police detectives around the country have mocked the miraculous way investigators on hit TV shows such as CSI: Miami ply their trade: Computers instantly identify matching fingerprints, labs return DNA samples in an hour and the crime unit supervisor, Horatio Caine, draws his gun as often as he flashes his badge.
The reality is more tedious: Crime scene investigators crawl around on their knees all day putting scraps of evidence in plastic bags, and technicians spend hours using magnifying glasses to detect the slightest differences between ridges on prints. Weeks pass as DNA tests are carried out at off-site facilities.
Now the very shows that have inflated juries' expectations for swift justice have helped attract the resources needed to modernize crime scene units - they're getting more high-tech equipment and anchoring their staffs with career-oriented specialists. Dallas is about to hire a civilian scientist to head up its crime scene response section for the first time.
"The best evidence is scientific evidence," said Ron Waldrop, Dallas assistant police chief. "Hiring someone with that education specifically is a good thing. It doesn't cost as much to train them. They're more or less there for a career."
Other influences, such as the high-profile O.J. Simpson trial, have focused the public eye on forensic evidence. But when the first CSI show made a splash in 2000, jury expectations immediately changed, said former Dallas County prosecutor Bill Wirskye.
Before, Mr. Wirskye would spend hours explaining to jurors the basics of DNA and how it helps a case. The show's popularity cut those presentations to minutes.
But jurors also became less impressed when there was not much forensic evidence. A lack of fingerprints or DNA could be a major hang-up. As a result, prosecutors have begun to cast a wider net for evidence, seeking, for example, lab tests on bullet casings that have passed through scorching firearm barrels.
"We really needed to try everything we could to get evidence in a case," he said.
That pressure trickles down to police investigators, said David England, a 20-year veteran crime scene technician for the Dallas police. Public expectations are far higher and sometimes unrealistic.
Fingerprints, for example, generally can't come from a surface rougher than your hand. "If you think you can get a print off a brick, come work for us," he said.
Fingerprints were first regularly used in the early 1900s. It could take days to match prints by combing through 300 or 400 ink-stained index cards at a time. The job was so stuffy that officers were sometimes assigned it as punishment.
Since the emergence of computerized databases in the early 1980s, the process has become far easier, though not as slick as seen on TV.
Today, police scan prints - potentially even just one ridge - into the Automated Fingerprint Identification System, which creates a unique digital ID and compares it to hundreds of thousands of others collected by law enforcement agencies.
Mr. England recently visited the scene of a burglary at an upscale apartment near downtown Dallas to be greeted by a man who was delicately pinching the top of a vodka bottle with two fingers.
He said he thought the culprits had taken a drink from the bottle during the burglary almost a month earlier, and he hoped they left fingerprints that could be recovered.
Though Mr. England said the expectation that prints might still exist after that long is typically unrealistic, he noticed the crook's hands had been sticky, perhaps because he touched a soda can.
Sugar residue left a usable print.
The crime scene response unit's fifth-story home in Jack Evans Police Headquarters downtown doesn't evoke images of Hollywood's forensic razzle-dazzle, but the modern facility - built in 2003 - does suggest an almost militant attention to detail.
While complex DNA tests occur off-site at the county-run Southwest Institute for Forensic Studies, the police unit has its fair share of high-tech toys.
In the lab, the Polilight console casts light of different wavelengths on objects taken from a crime scene, allowing investigators to spot fibers and body fluids that might yield DNA evidence. A state-of-the-art climate-control system, which had to be airlifted into the facility, better preserves trace evidence.
In the office, a whirring electronic filing system keeps track of countless green fingerprint envelopes.
The evidence processing room - off-limits to most police officers for fear of contamination - features ceiling-high driers that prepare items like dusty shirts and bloody rocks that are plucked from the scene for examination.
As technology advances, police have hired more civilian scientific experts to work alongside sworn officers. Officers often transfer between units, and using civilians allows the department to ensure that crime scene investigators maintain expertise without constant training.
There are now 30 non-sworn and 38 sworn positions in the Dallas crime scene unit, and a non-sworn "forensic services administrator" - the equivalent of a police captain - will soon be hired to lead them, said Lt. Marc Hearn, who supervises violent crime investigators.
The next trainer of detectives for crime scene analysis will also be a civilian, along with six supervisors who will eventually replace police sergeants, he said.
But television shows, fancy gadgets and training aside, Detective Scott Bazan says old-fashioned elbow grease is what solves cases. He recalls crawling under a Suburban to finally find bullets fired in a drive-by shooting weeks earlier.
"You have to think creatively," he said. "And you have to get dirty at times."