Two teens accused of killing a 79-year-old Willmar woman have been indicted on first-degree, premeditated murder charges.

Brok Junkermeier, 19, and Robert Warwick, 17, each face two counts of first-degree murder in the July death of Warwick's grandmother, Lila Warwick. If convicted, the pair could face life in prison, without parole, according to indictments filed Wednesday in Kandiyohi County.

The charges come after a grand jury met for several days to review evidence. In Minnesota, a premeditated murder case cannot be prosecuted unless a grand jury has convened and issued a first-degree murder indictment.

"It's something that we expected, that we were preparing for," said Kent Marshall, public defender for Junkermeier. "The charges are as bad as they get."

Prosecutors allege that Robert Warwick hatched the plan that led to Junkermeier's attack on the elderly woman in her home. Early one morning in late July, Junkermeier allegedly slashed Lila Warwick's hand with a swordlike knife and forced her to write him a check for $1,500 before choking and stabbing her to death, according to second-degree murder charges filed in August.

A third teen charged in the case, Devon Jenkins, was not included in this week's indictments. Jenkins, 16, is accused in a juvenile petition of driving Junkermeier to the house and acting as the lookout.