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Cops: Iraq War veteran Routh told sister he killed two people

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The Iraq War veteran charged with killing a former Navy SEAL sniper and his friend on a Texas shooting range told his sister that he "traded his soul for a new truck," according to an arrest affidavit released by a justice of the peace.

Eddie Ray Routh also said he wanted to drive to Oklahoma to avoid Texas authorities, according to an Erath County arrest warrant.

Erath County Sheriff's Capt. Jason Upshaw said Monday that Eddie Ray Routh drove to his sister's house in Midlothian after the shootings on Saturday and told her that he killed two people.

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On Sunday, Sheriff Tommy Bryant said Routh told his sister "what he had done." Bryant did not provide more information at the time.

Routh, a member of the Marine Corps Reserve, is being held at the Erath County Jail on $3 million bond. Routh is being held in isolation and a stun gun was used on him after he became combative over returning a dinner tray. According to Erath County Sheriff Tommy Bryant, Routh was placed on suicide watch.

Related: 

Murder of former Navy SEAL turns spotlight on veteran hunting and shooting clubs 

Ex-Navy SEAL sniper Chris Kyle died pursuing his passion