In the three years since the deadliest biker shooting in U.S. history, Fort Worth correspondent Emily Schmall has meticulously gathered documents, reports and court records to put together a spreadsheet that she used to exclusively report that prosecutors had indicted a biker for murdering a man who was shot twice by Waco police.

Several sources had given Schmall the records – law enforcement incident reports, officers’ notes, thousands of crime-scene pictures, audio interviews, surveillance and dash-cam footage and forensic analysis – in 10 rounds of evidence the state has shared with defendants’ attorneys.

Schmall's exclusive was based on meticulous documentation of case records from sources.

Ap 18129643702018 Walker

This booking photo shows Glenn Walker, charged with the murder of a rival motorcycle gang member outside the Twin Peaks restaurant in Waco, Texas, May 17, 2015. The man Walker is accused of killing was shot three times: once with a pistol linked to Walker, and two times by a SWAT team rifle.

McLennan County Sheriff's Office via AP

After the May 2015 shooting that left nine bikers dead, Schmall discovered that a family friend, a Dallas-based physician, knew someone who had worked on the autopsies. The friend made an introduction, and the medical examiner helped explain how to cross-reference the firearms and ammunition analyses with the patterns of the nine dead bikers’ gunshot wounds.

Schmall’s extensive spreadsheet integrated the autopsy reports, firearms analyses and ballistics evidence, including the names and serial numbers of the weapons, to whom they were traced, where they were recovered from and whether they were linked to a death or injury.

Her work paid off last week when prosecutors handed down the first murder charges in the case. Schmall was able to exclusively report that prosecutors had charged one of the bikers for murdering a man who was shot twice by a SWAT officer. Using the spreadsheet, she was also able to report that a pistol federal agents had traced to the biker was found in the backseat of the SWAT officer’s police vehicle. It is not entirely clear whether shots from the officer or shots from a biker actually killed the man.

Schmall's story got great play, appearing in the Waco Tribune-Herald, the Houston Chronicle and the Dallas Morning News, and as far afield as Belfast, Northern Ireland. It also appeared prominently on Yahoo and MSN, ABC News and in broadcast outlets across the U.S.

For persistent, investigative reporting that exclusively illuminated potential problems with a shifting strategy in a closely-watched case, Schmall wins this week’s Best of the States.