Attorneys for Jerman Neveaux want to claim insanity in the killing of a Jefferson Parish Sheriff's Deputy last summer. 

Neveaux's attorney Martin Regan filed a motion Monday in 24th Judicial District Court saying his client is "severely affected" by lead poisoning and asked a judge to allow Neveaux to plead not guilty by reason of insanity. 

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Neveaux pleaded not guilty in court last October following a grand jury indictment for first-degree murder. 

Neveaux is accused of shooting Deputy David Michel on June 22, 2016 outside the Dunkin’ Donuts on Manhattan Boulevard.

Michel was patrolling the Pebble Walk neighborhood when he spotted Neveaux following someone on foot, according to JPSO. Michel, who was wearing street clothes, stopped Neveaux and attempted to search him. At some point during the encounter, Neveaux allegedly pulled out a stolen gun and opened fire on the deputy, fatally wounding him.

Sheriff Newell Normand said a witness told authorities that Neveaux grabbed Michel by the hair and neck after shooting him the first time and then fired two additional rounds into his body.

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A manhunt following the shooting ended with Neveaux being captured in the backyard of a house on London Crossing. Video showed arresting officers beating Neveaux after he was apprehended.

MORE: Witness describes frightening encounter with suspect, officers during manhunt

Regan told the New Orleans Advocate he has "documentation" that Neveaux's mental health was affected by lead poisoning but refused to divulge how he was poisoned. "All of that will come out publicly," Regan said.

A hearing on motions in the case is scheduled for Thursday, but Neveaux's attorney said it likely will be delayed. Jefferson Parish District Attorney Paul Connick has said he will seek the death penalty in Neveaux's case.