Prince George’s County police officer LaToya Holmes, the lead investigator in a homicide in Oxon Hill, Md., holds an evidence bag containing a shell casing at the crime scene. (Evelyn Hockstein/For The Washington Post)

The body sat slumped near the dresser that Heather Jordan was inspecting for fingerprints. On the other side of the bedroom, her colleague took a small saw to some drywall, hoping to retrieve remnants of a bullet that had pierced the plaster.

The buzzing of the saw stopped.

“Did you find it?” Jordan asked.

“No bullet,” Cpl. David Vastag said. “I got a bunch of dead bird parts, though.”

Through a cloud of dust, Vastag pulled a tangle of desiccated feathers and twigs from a gap between the drywall and cinder block.

Heather Jordan, a Prince George’s County crime-scene investigator, dusts for fingerprints on a dresser at a homicide scene in Oxon Hill, Md. (Evelyn Hockstein/For The Washington Post)

The gap extended down three stories, where Vastag suspected the bullet disappeared.

“So on TV, you know how they always find something?” said 1st Sgt. Charles Montgomery, over Vastag’s shoulder. “It ain’t necessarily so.”

Television crime shows often end neatly with investigators arriving at a heinous scene, collecting decisive evidence and identifying a suspect in the span of an hour (with commercial breaks). But clues left at actual crime scenes aren’t always conclusive or easy to find. Fingerprints don’t always appear or a DNA sample may be muddied by dozens of other people who touched an object long before a crime occurred. Investigators don’t always uncover blood, an ammunition casing or other damning evidence.

In real life, recovering clues is physically, emotionally and mentally grueling work, as a night with a squad of crime-scene technicians in Prince George’s County showed.

“It’s going to be one of those extra long nights,” Montgomery said, crouched on his hands and knees looking underneath the dresser for more evidence. “I can see it now.”

‘Don’t touch that’

Montgomery’s team headed to an apartment in Oxon Hill, Md., shortly before midnight on a Friday. Officers found a man fatally shot in the bedroom.

As soon as a scanner finished capturing images of the scene — to later create three-dimensional models of the apartment — the team got to work.

Jordan drew diagrams of the apartment, depicting the positioning of the body (sketched as a stick figure), possible bullet holes and blood spatter. Vastag took photos. Officer LaToya Holmes, leading the investigation, prepared to bag beer cans, cigarette butts and other items to be tested later for DNA or fingerprints.

“We have very minimal evidence,” Holmes said. “We want to get down to the nitty-gritty.”

It helped that the apartment was small — easier to zero in on the proper evidence to collect. But it also made the work trickier. A dozen evidence technicians, police officers, homicide investigators and a medical examiner all tiptoed around potential clues through the night. Warnings of “don’t walk here” and “don’t touch that” wafted through the stuffy apartment along with the smell of stale cigarette smoke and ammonia.

Odors from crime scenes often linger in investigators’ memories. The meat aisle in a grocery store might smell strongly of blood, taking them back to a particularly gruesome case. Or the stench of rotting food reminds them of the day they spent digging through mounds of trash searching for a discarded gun.

“I breathe through my mouth a lot,” said Jordan, who has been a crime-scene investigator since 2011. “You walk somewhere, you smell something and something brings you back.”

Investigators, always wearing gloves, try to avoid contamination and touch only what they must.

At the Oxon Hill apartment, that meant a stereo blasting music the moment they stepped inside continued to stream rhythm and blues during the seven hours they processed the scene. The only time the stereo was touched was to swab the volume knob for possible DNA.

The evidence technicians often arrive at scenes where televisions and radios already are blaring, usually ramped up to hide an argument, gunshots or screams. Investigators work through the noise or turn the volume down after collecting what they need. But other sounds are harder to ignore.

Like the persistent ringing of a phone in a victim’s pocket — a jangling reminder of someone else’s fret.

“Someone is looking for them, and they don’t know that they’re dead,” Jordan said.

‘One chance to get it right’

Hours into the Oxon Hill investigation, yellow placards dotted the bedroom: No. 1, a shell casing; No. 2, drug paraphernalia; No. 3, a beer can; and on and on.

“Okay, LaToya,” Jordan asked Holmes after collecting fingerprints, “what else is important here?”

Investigators scanned the apartment, and everything was a potential clue. A screw in the wall from a distance looked like a bullet hole. Same with a cigarette burn in a comforter.

“We know there is evidence in this wall or next to this wall,” Montgomery said as he stood over the dead man, “but we can’t get to it until the body is moved.”

The state of Maryland has custody of a body after a homicide, so investigators can’t touch the deceased until a medical examiner properly prepares the body for autopsy. Doing otherwise could contaminate vital evidence.

That is why investigators don’t cover bodies with sheets, move them from the scenes of crimes that occur in public view or outline them in chalk.

That restraint is because of the theory that drives crime-scene work, called Locard’s exchange principle, which holds that anytime someone makes contact with something they both leave and take away physical evidence. That’s why Jordan’s hair is always tied in a bun, why investigators sometimes don biohazard suits and why many are wary of touching door handles in public places.

Thirty years ago, scene investigators mostly snapped photos and dusted for fingerprints. But technology has improved. DNA tests can connect crimes to possible suspects through national databases — and through ever smaller samples. Rather than needing a whole drop of blood to test for DNA, it can be gathered on objects that have simply been touched.

Shows such as “CSI: Crime Scene Investigation” and “NCIS” highlight — and sometimes exaggerate — such advancements while also conditioning jurors to expect clear forensic evidence in their case, said Hayden Baldwin, head of the International Crime Scene Investigators Association.

But less than 5 percent of law enforcement agencies have full-time crime-scene investigators, said Baldwin, who said he specifically watches crime dramas to see what jurors are likely to expect when he testifies in court.

“I’ve never solved a crime within an hour or have had DNA results back within five minutes,” Baldwin said.

The evidence that crime-scene investigators collect is important, but its analysis is vital.

Bad analysis not only can lead to an innocent person being jailed but it also can allow a perpetrator to roam free, said University of Virginia law professor Brandon Garrett.

“It’s a long-standing problem where there are a lot of criminal cases where there is information that is useful but not collected and tested, or really important crime-scene evidence that was handled improperly,” said Garrett, a criminal justice expert.

A national movement to reform techniques has risen, with the Justice Department recently expanding its review of forensic testimony by the FBI.

Done right, forensic analysis can bring justice for victims and yield important answers.

Two years ago, when a 3-year-old girl died after her father kidnapped her and engaged in a shootout with police, Prince George’s investigators had to determine whose bullet struck the child. Police officers — who hadn’t known the girl was in the car with the suspect — feared that one of their guns fired the fatal shot. Investigators worked quickly and found that the father shot his daughter and himself.

“The police department gets one chance to get it right for the victims and families,” said William F. Greene, a 35-year investigator who is director of technical operations for the Prince George’s Crime Scene Investigation Division.

‘Watch the blood’

By about 3:45 a.m., the medical examiner arrived.

“We’re going to move him,” she said. “Just watch the blood, okay?”

With a handful of officers and investigators, the medical examiner, in scrubs, carried the man onto a tarp, flipped him over and counted bullet wounds.

They wrapped his hands in paper bags and taped the bags shut — later to scrape material from under his fingernails — before zipping up the body bag and carrying him out.

Investigators handle more than homicides. They investigate sexual assaults, child abuse, robberies and burglaries. They work surrounded by the lives of crime victims: family portraits on the walls, a Barbie discarded in the corner, an abandoned pot of taco meat cold on the stove.

Some days can be mundane. Others days, haunting.

Sometimes, they are sent to a psychiatrist to talk through what they have seen. More often, they lean on dark humor or distractions.

During a brief lull at the apartment, someone stuck a pen in the bun piled high on Jordan’s head.

“You look like a Teletubby,” Greene said as the pen wobbled like an antenna.

The joke was a relief valve amid the gruesome hours they’d spent since midnight without eating, drinking or even bathroom breaks.

By 7 a.m., it was time to go. The placards were pulled up. And investigators conducted a final check under tables, between mattresses and behind sofas.

More work awaited at the lab. But for now, it was time for the investigators to shut the door and lock up the apartment.

Inside, the music played on.