Parents accused of killing children test insanity defense

(FOX 13) - Jon Jonchuck is accused of the unthinkable - throwing his daughter off a Bay Area bridge in 2015.

In a shockingly-similar situation, Tampa police say Shakayla Denson dragged her crying daughter into the Hillsborough River last month and let her drown.

Witnesses said they watched the little girl struggle in the water.

Now the question is, will the insanity defense be used in both of these cases? Furthermore, will it work? 

Attorney Anthony Rickman says proving insanity may be a long shot.

"He may have had some sort of mental illness but it didn't rise to the level of legal insanity," said Rickman. "The defense has to prove that, at the time of the offense, that he suffered some sort of mental health illness and that mental health illness prevented him from understanding right from wrong."

The insanity defense did not work for double murderer Julie Schenecker. The public’s first images of Schenecker showed her shaking uncontrollably as she was escorted out of the police station.

The mother of two was convicted of killing her two kid,s Beau and Caylx for being "too mouthy."

But Rickman believes there is one case that could actually be successful with an insanity defense.

"Mikese Morse screams [of] a history of mental health," said Rickman.

Morse is accused of running over and killing a father who was bike riding with his two boys.

Morse posted bizarre rants on social media claiming the devil made him do it.

Weeks before, Morse showed up to a police substation and warned an officer if he was allowed to leave he would hurt someone.

The officer had Morse detained under the Baker Act.

Morse's mother, Khadeeja Morse said she tried for years to get their son help but was turned away.

"We really need to remember this is a mental health issue. This is a failure of the system and this didn't have to happen," explained Morse.