Fire Captain Nabbed in 3 Cold-Case Murders David Watson faces charges in deaths of ex-wife, mother-in-law By Arden Dier, Newser Staff Posted Apr 28, 2015 10:44 AM CDT 9 comments Comments This April 26, 2015 photo provided by the Pima County Sheriff's Department shows David Dwayne Watson in Tucson, Ariz. (Pima County Sheriff's Department via AP) (Newser) – David Watson was battling his ex-wife, Linda, for custody of their daughter when the woman vanished from her Tucson home on Aug. 20, 2000. In 2003, Watson was locked in another custody battle over the same girl with his former mother-in-law, Marilyn Cox, when she was gunned down after a court-mandated visit with her granddaughter, along with friend Renee Farnsworth, outside of Linda's home where Cox had been living. Linda's body was found in the desert that year and identified in 2011, but no charges were laid in connection with the three murders, the AP reports. Now, police say they've finally arrested the man they've long considered the prime suspect: Watson, a local fire captain described as a "very dangerous" man, who faces three counts of first-degree murder. Tucson News Now reports DNA results and tips from the public back up the arrest. "A lot of the information we can't talk about right now," a deputy sheriff tells the Washington Post. "If for some reason this man is released, we don’t want him to be able to guess the identities of our witnesses from the information we've released." However, a family friend tells KVOA that Cox had led Watson through Linda's home before her death and showed him a gun she kept beside her bed. "She ... wanted him to know that she was not going to be as easy to take as poor little Linda," the woman says. In a statement, per Tucson News Now, Cox's sister says her family is "overjoyed" by the arrest. "After so many years we sometimes felt it would never happen." Watson, 46, joined the Tucson Fire Department in 1995 and rose through the ranks to become captain in 2007; the department says it wasn't aware he was a murder suspect. He's being held on $2 million cash bond.