Updated

The mistrial for highway shooter Charles McCoy Jr. (search) might make his attorneys less likely to accept a plea deal even though second trials tend to favor the prosecution, experts said Monday.

A hung jury was declared Sunday after four days of deliberations in the trial of McCoy, 29, charged with 12 shootings that terrified Columbus-area commuters over five months in 2003 and 2004. The defense had acknowledged he was the shooter but argued he was innocent by reason of insanity.

Prosecutor Ron O'Brien (search) has said he will retry McCoy, who could have faced the death penalty if convicted of murder for the November 2003 death of Gail Knisley, the only person killed in the shootings.

O'Brien, who maintains McCoy knew his actions were wrong, said he would decide Tuesday whether to drop the death penalty specification from the indictment because of all the medical evidence revealed at trial.

He said he spoke on Monday with Knisley's family and said they don't believe the death penalty is the only way to get justice.

O'Brien said he remains open to a plea negotiation but believes the evidence still supports some form of murder charge.

Some legal experts said Monday, however, that McCoy's attorneys might be less likely to accept a plea deal since at least one juror firmly believed McCoy did not understand the shootings were wrong.

"You'd have to interpret this as a minor victory for the defense," said Joshua Dressler, a law professor at Ohio State University (search). "This was a much stronger insanity claim than is usually the case."

A second trial, though, typically favors prosecutors because the defense has revealed their secrets, said Dr. Park Dietz, the psychiatrist who testified for the prosecution in the insanity trial of Andrea Yates, the Texas woman who drowned her five children in a bathtub.

"At a retrial, the government has had time to prepare," Dietz said. "They have time to rebut anything that surprised them at the first trial, or prepare to immunize the jury at opening statements."

Residents and commuters were frightened for months as bullets struck vehicles and houses at varying times of day and night along or near Interstate 270, the highway that encircles Columbus.

McCoy's attorneys insisted he did not understand his actions were wrong because of delusions from his untreated paranoid schizophrenia. However, the prosecution's psychiatrist said that, despite the delusions, McCoy showed he knew his actions were wrong by steps he took to avoid capture.