Ten days of testimony in a federal court competency hearing shed new light on the man charged in the abduction of Elizabeth Smart but also raised some persistent questions about his mental state.

The federal hearing ended Friday amid a flurry of contentious sniping over the validity of mental health evaluations and observations conducted on Brian David Mitchell since his arrest in March 2003.

In his closing argument, federal public defender Robert Steele said the question before the court is narrow and difficult.

"It's a close one, with science and opinion going both ways," Steele said.

During the hearing, prosecutors called witnesses who said Mitchell, 56, is a controlling, devious sexual predator who sang hymns incessantly in court to frustrate and disrupt proceedings before he was removed.

Mitchell's defense attorneys countered with experts who said he was awaiting martyrdom and a miraculous rescue from prison by God.

A decision on Mitchell's competency for trial rests with U.S. District Judge Dale Kimball. His ruling _ expected early next year _ will determine if the case heads to trial or toward medical treatment designed to restore Mitchell's competency.

Mitchell faces charges of kidnapping and unlawful transportation of a minor across state lines. If eventually tried and convicted, he could spend the rest of his life in prison.

"It's very difficult to figure out what's going on inside someone's head," testified Dr. Richart DeMier, a forensic psychologist with the U.S. Bureau of Prisons who evaluated Mitchell.

The proceedings are in part a replay of hearings in a state case, where mental health experts diagnosed Mitchell with a delusional disorder and a 3rd District judge twice ruled him incompetent.

In 2008, the same judge ruled against forced medications for Mitchell, leaving the case essentially in limbo until the U.S. attorney's office got involved.

Smart was 14 when she was awakened in her bed and whisked away at knifepoint in June 2002 to a hillside campsite three miles from her Salt Lake City home. She was recovered in March 2003 after nine months of homeless rambling with Mitchell and his now-estranged wife Wanda Eileen Barzee in Utah and California.

In October, Smart, now 22, told her story for the first time, recounting a forced marriage to Mitchell. Smart testified that Mitchell was obsessed with sex and raped her as many as four times a day. She called his espoused dedication to religion false and said he plied her with alcohol and drugs to lower her resistance to his sexual advances.