TUCSON (KGUN9-TV) - An ex-wife recants an alibi, now former Tucson Firefighter David Watson is on trial for three murders.
His first ex-wife, her mother, and her mother's friend.
The death of Linda Watson in 2000 and the 2003 murders of her mother Marilyn Cox and her friend Renee Farnsworth were cases that had gone cold until Watson's second wife admitted the alibi she gave Watson was a lie.
David Watson triple murder trial: Prosecutor pegs case on ex-wife recanting alibi, Defense attorney questions her motives. @kgun9
— Craig Smith (@csmithKGUNTV) October 5, 2016
Now the trial is beginning that will decide if Watson is guilty of three murders.
Prosecutors say the case hinges on a child custody dispute so vicious it led to three murders.
READ MORE: New photos released in Watson investigation
Prosecutor Jonathan Mosher says David Watson was so determined to keep custody of his daughter Jordan he killed ex-wife Linda Watson to keep her away from a custody hearing.
When she seemed to have disappeared he got custody by default.
Mosher says Watson's second wife Rosemary told detective he was home at the time Linda Watson disappeared when he really was out until dawn.
READ MORE: Background on David Watson cold case
"She looks out and there he is at the back of his Jeep cleaning it out. She doesn't see what. She doesn't see what he's cleaning out. She knows that he came inside carrying a box of gloves you know gloves like a firefighter, paramedic would have," said Mosher.
Linda Watson's mother Marilyn Cox believed Watson killed her daughter.
After she won child visitation rights, someone shot and killed her and Renee Farnsworth in front of Linda Watson's house.
Again second wife Rosemary Watson said he was with her. Later she admitted he went out and made another suspicious return.
"He was sweating, pale eyes wide, panicked. She takes one look at her husband, she knows something is wrong. She doesn't know that Marilyn and Renee have been gunned down at that point. And she says, 'What's wrong?' Defendant comes in, turns out the lights, kisses the girls goodnight, leaves the room with Rosemary, takes off his clothes, says, 'Wash these,' and gets in the shower."
Mosher says Rosemary Watson lived in fear and kept David Watson's secrets until she divorced him and told Detectives what she knew but it still took another eight years to arrest David Watson until remains found in the desert matched Linda Watson.
"She needs to disappear." David Watson's 2nd ex wife testifies he said that of Linda Watson. On trial for her murder and 2 others. @kgun9
— Craig Smith (@csmithKGUNTV) October 5, 2016
Rosemary Watson was the alibi for former Tucson Firefighter David Watson in the murder of his first ex wife, that woman's mother and a friend. But today she is testifying against him.
She retracted her statements and then investigators identified Linda Watson's remains fifteen years after she disappeared.
Prosecutors say this case hinges on a brutal custody dispute over the Watson's daughter Jordan.
Once she retracted her alibis for David Watson, Rosemary Watson said the day Linda Watson disappeared, she saw David Watson at his car close to dawn, acting like he was cleaning something out.
He denied having anything to do with his first wife's disappearance and she did not tell investigators what she saw.
Three years later, someone killed Linda Watson's mother Marilyn Cox and a friend who was with her, just minutes after they dropped off David Watson's daughter.
She told investigators he came home sweaty and in a panic, but she said nothing.
"There was no way that I wanted to believe that it was possible that he was involved....I loved him and I just wanted to protect my family," said Rosemary.
Rosemary Watson divorced David Watson in 2007.
A few months later she told investigators what she really saw that night.
Defense attorney Mike Storie questioned her motives for changing her story. He also said Linda Watson had alcohol, employment problems and conflict with her new boyfriend and that she sometimes spoke of just running away.