LAPD HEADQUARTERS, LOS ANGELES, CALIFORNIA

APRIL 2012

The elegant lines and windowed walls of LAPD Headquarters face due north, toward Los Angeles City Hall, rumored to be the most haunted building in a wicked town.

The elite Robbery Homicide Division, or RHD, is located on the fifth floor of LAPD Headquarters, not haunted by anything other than its storied past. RHD is composed of four sections (Robbery, Homicide, Gang Homicide, and Special Investigation), plus a Cold Case Homicide special section, and isn’t limited by geographical divisions but rather tasked with investigating or providing support for high-profile crimes on any side of the freeways and boulevards that slice Los Angeles into racially divided islands. The triumphs and foibles of LAPD’s crackerjack detective division have set fire to countless imaginations, inspiring iconic characters from Dragnet’s Joe Friday to Michael Connelly’s Harry Bosch.

In 2012, one of the rising stars in Homicide even had a parrot named Joe Friday.

Five years before I interviewed her at Little Dom’s, Detective II Mitzi Roberts, LAPD Robbery Homicide Division, left for work on the morning of April 26, 2012, knocking her elbow on the counter as she grabbed for her travel mug of black coffee.

“Fucker!”

“Fucker,” echoed Joe Friday. It was the only word he said. She adopted yet another Doberman pinscher—four and counting—and named him Tucker so she could play it off for her mom.

The day before, she’d been to Davis and back, a seven-hour drive, with her partner, Rodrigo Amador, to interview the Klitschko brothers about the Exum Speight case, in which a boxer killed his manager. Roberts had a manner both straightforward and intimate that put suspects and victims alike at ease. She could (and did) easily charm a couple of boxers in Davis, Rick James, Phil Spector, and that guy who thought he was Haile Selassie and had his son’s head in his freezer.

The truth was, horrors happened on a good day working homicide. The day-to-day slog was the bitch. Roberts and Amador were still pushing paper and organizing evidence from the task force on the murdered Giants fan at Dodger Stadium case.

The halls of RHD fizzed with another kind of case that day. You’d never have known it to look at the faces of the detectives hunched over countless screens and binders, banging out phone number after phone number, slagging over their cubicle walls.

Roberts worked in the Cold Case Special Section, or CCSS. Formerly the Cold Case Homicide Unit (CCHU), the CCSS was born when forensic advances in DNA science prompted the National Institute of Justice to offer grants to local law enforcement, enabling them to screen thousands of cold cases with the hope that trace DNA evidence might have been preserved. This DNA might then be matched with a suspect from the national DNA database called CODIS (Combined DNA Indexing System—both the software and the initiative).

The history and science of DNA identification both fascinated and confounded me.

The FBI piloted CODIS in 1990 with fourteen state and local laboratories. In 1994, Congress passed the DNA Identification Act, which authorized the FBI to create a national DNA database of convicted offenders as well as separate databases for missing persons and forensic samples collected from crime scenes. Cohesive national protocols developed for DNA analysis made forensic evidence collection simpler and enabled identification using smaller and sometimes degraded samples.

LAPD sex crimes and homicide detective David Lambkin and deputy district attorney Lisa Kahn shared a passion for solving cold cases, scheming behind overloaded filing cabinets about the developing forensic possibilities that might crack them open—and the nine thousand more behind them. The DOJ funded a unit, the CCHU, to screen old evidence, using fingerprint, ballistic, and DNA databases.

Located at the former Parker Center headquarters, the original seven members of the CCHU were squeezed into a windowless 250-square-foot utility closet in which there were one and a half computers that almost worked, one wall of telephone jacks that required the detectives to constantly pass headsets back and forth, and a door you couldn’t open unless someone rolled their chair out of the way.

Lambkin and Khan recruited detectives Tim Marcia, Richard Bengtson, José Ramirez, Vivian Flores, and Cliff Shepard, with Rick Jackson as the assistant officer in charge. They screened for viable potential DNA evidence, uploading relevant results onto local, state, and federal databases to see if that particular DNA matched a genetic profile. If it did, they worked up their guy and tracked him down. DNA identification was so new, they played for time and used fingerprints and interviews while enough technicians were trained to handle the seemingly endless caseload. It sometimes took years to get screening results.

I hung out with Rick Jackson, the real-life Harry Bosch, who has a die-hard classic cop mustache, infectious confidence, and a knack for telling stories. He told me he’d bonded immediately with his new partner Tim Marcia. Marcia was witty, sometimes brooding, with hard ethics and a mouth to match. Together they juggled plates, incorporating emerging technologies into classic gumshoe work.

American biologist James Watson and English biophysicist Francis Crick unveiled their sea change discovery of the DNA helix in 1954, along with Maurice Wilkins and Rosalind Franklin.

DNA fingerprinting is a different animal—its current incarnation familiar to anyone who’s been arrested and had their cheek swabbed or spit into a tube sent from 23 and Me. The process of determining an individual’s unique DNA characteristics was developed only six years previous to the inception of CODIS in 1990. The forensic applications of DNA fingerprinting captured the attention of the public.

In 1984, Sir Alec Jeffreys of the Department of Genetics at the University of Leicester developed DNA fingerprinting, also known as DNA profiling. About 99.9 percent of DNA sequences, the building blocks that make us human, are the same in all human beings; the other 0.1 percent make us not just human but individuals. This 0.1 percent aids criminal investigations, enables medical advances, provokes legal battles, allows familial identifications, and holds limitless possibility.

The double helix itself contains clues to not just whodunnit but also who we are and why. A certain genetic profile combined with plasticity affected by activating environmental factors can indicate a propensity for aggression. For example, violent offenders and law enforcement officials alike often share the famed MAOA gene, or warrior gene.

DNA fingerprinting is based on the statistical calculation of the rarity of the produced profile of alleles within a population. A gene is a unit of hereditary information made up of that twisty beasty DNA, a complex molecule that codes genetic information. An allele is a rebel—a variant form of a gene that also codes for sequences. Copies of each gene cozy up together at a specific locus (location on a chromosome), one from each parent. The copies aren’t necessarily twinsies.

Today’s system of DNA profiling identifies short tandem repeats (STRs): simple repeating sequences of alleles. STRs vary in length, enabling scientists to distinguish one DNA sample from another. Genetic fingerprinting isolates these STRs and calculates the probability that the sample screened belongs to a specific individual. The FBI has identified thirteen core STR loci routinely used in the identification of individual offenders in the United States.

While the CCHU scrambled for properly trained analysts, they combed through fingerprints, talked to family members, and dug through databases like NamUs (the National Missing and Unidentified Persons System, established in 2007) and the Doe Network (the International Center for Unidentified and Missing Persons, founded in 1999).

As ancestry became a national obsession, Lambkin, Khan, Marcia, Jackson, and the rest of the intrepid CCHU Don Quixotes moved out of their closet and into a room with wide windows and a sweeping view of their city of bones. They became the CCSS. Detective Mitzi Roberts joined in 2010, and they took on the unofficial motto of Connelly’s fictional Harry Bosch: Everyone matters or no one matters.

Cold cases were a long game, sometimes taking years for the screenings to cycle through the bogged-down system. On a bad day, bad weeks or months even, the endless rows of files could make the most seasoned detective flirt with hopelessness. Then, bam, a case-to-case hit and you were back full throttle.

Roberts and her then partner Amador first saw the name Samuel Little when the screening efforts of the CCSS connected DNA from two LA homicides in the late eighties to a man named Samuel Little, a.k.a. Samuel McDowell. The two four-inch-wide three-ring binders, known as murder books, carried all the hallmarks of a sexually motivated serial killer.

On May 6, 2009, a CCSS detective submitted evidence from the 1989 murder of Guadalupe Apodaca to the Serial Investigation Division, then on to Bode Technology lab for DNA analysis.

On March 1, 2010, epithelial cells extracted from the fingernail kit from the murder of Audrey Nelson were submitted for analysis.

On the morning of April 26, 2012, DNA fingerprinting confirmed a case-to-case match, linking two cold case homicides with a known criminal named Samuel Little through a national database. A case-to-case: the holy grail of homicide investigation. However, even the holy grail is only a start. High-risk lifestyles, including drugs and prostitution, can mean that multiple DNA profiles are present on a victim’s body. DNA alone won’t likely get you an arrest.

Roberts was still going to have to make a case corroborating the DNA evidence, at the same time tracking him and trying to get him into custody. He could have been out there stalking his next victim even as she reviewed the case files.

Roberts slid the first murder book toward her and opened a world. It was never laid out for you neat and nice like a mystery novel, but the story was in there somewhere if you knew how to work backward from the end.