HELENA, Mont. (AP) — A Missoula man convicted of shaking his 3-month-old son to death will get another chance to vacate or lessen his 40-year sentence.

The Montana Supreme Court ruled Tuesday that a district court must reconsider Robert J. Wilkes' appeal in the 2008 death of his son, Gabriel.

Wilkes claims public defender Scott Spencer provided ineffective counsel by calling no witnesses other than the father and never challenging the state's shaken-baby syndrome theory.

The Montana Innocence Project began representing Wilkes in 2011. The group presented testimony from pathologists and pediatricians that Gabriel suffered from a rare and often fatal liver disorder that presents effects similar to abusive head injuries.

The high court sent the case back to District Judge Ed McClean to reconsider Wilkes' petition for post-conviction relief.

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