A husband charged with killing his wife's teenage lover got a rifle two weeks before the boy was shot to death outside his home, investigators in Tennessee testified Tuesday.

A grand jury is considering whether Eric McLean should be charged with first-degree murder in the shooting death of 18-year-old Sean Powell, a former student at the high school where McLean's wife, Erin, was a teaching intern.

Powell was shot to death March 10 as he sat in a car in front of the couple's home.

In a jailhouse interview last week, Eric McLean, 31, acknowledged shooting Powell but said it was an accident.

McLean said he knew his wife was having an affair with the former student but said he could not leave her because he still loved her. The day of the shooting, he said, he was outside his home when Powell drove up. He said he told Powell to leave, but the teenager ignored him. That is when he called an emergency dispatcher saying there was an intruder, he told NBC's "Today Show."

Asked if he shot Powell, McLean responded, "Yes." Asked if it was an accident, he also quickly said, "Yes."

Prosecutors said there was evidence Powell had raised his hand in a defensive gesture as McLean approached him, suggesting a premeditated act.

Powell was shot with a rifle that Eric McLean told police he got two weeks earlier, according to court testimony. McLean told investigators he intended to use the weapon to shoot himself.

During the hearing Tuesday, the tapes of calls to the emergency dispatcher were played. In the initial recording, Eric McLean was heard saying an intruder was at the couple's home. Seven minutes later, Erin McLean called saying her husband had shot Powell.

Eric McLean and Powell's mother have both said they believed Erin McLean was having an affair with the former student. Erin McLean, 30, left Knoxville after the shooting and was last known to be staying with relatives. Her husband's bond was set at $150,000