COVINGTON, Tenn. (AP) -- A Texas teenager has been sentenced to life in prison for murdering a Tennessee state trooper.

Under the sentence handed down Thursday in Covington, 18-year-old Alejandro Gauna will be eligible to apply for parole in 51 years.

A trial jury convicted Gauna on Wednesday of first-degree murder for shooting Trooper Calvin Jenks during a traffic stop near Covington in January 2006.

Gauna's jury had two sentencing choices -- life in prison without parole or life with the possibility of parole in 51 years.

When the jury was unable to reach a decision, Judge Joseph Walker stepped in and issued the only sentence available to him -- life with a chance at parole.

Gauna will be 69 years old when that chance comes around.

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