Associated Press

SIOUX FALLS, S.D. - Jurors in the trial of a Sioux Falls man accused of murder for strangling his wife and infant son found him guilty but mentally ill Friday night.

Brian Leingang, 33, was charged with killing Melissa Leingang, 38, and the couple's 6-month-old son, Caden, in the family's trailer home in April.

The verdict, reached after more than seven hours of deliberation, means Leingang would serve a maximum of life in prison without parole and receive psychiatric help, the Argus Leader reported online Friday night.

No sentencing date was set.

During the trial, doctors testified that Leingang had a history of psychotic attacks going back to the 1990s when he admitted having a problem with methamphetamine and other drugs.

A forensic psychiatrist from Minnesota, Dr. Michael Farnsworth, had testified that Leingang was insane at the time of the killings and that it was brought on by cough medicine.

Leingang had testified to taking cough syrup the week of the killings because it gave him the same feeling that meth gave him.

Farnsworth said the cough syrup could have triggered a series of events leading to the killings.

Leingang thought he was possessed by the devil, Farnsworth testified.

On Friday, prosecutor Dave Nelson said Leingang was trying to shift the blame.

"That's how a human being who kills his family lives with himself," Nelson said. "Blame drugs. Blame the devil."