The word “mistrial” floated around twice last week during the second-degree murder trial of Troydell Simmons, who is charged in the July 2009 killing of a Carencro man.

On the second occasion, defense attorney Harold Register called for and received a mistrial after a 15th Judicial District judge ruled that prosecutor Pat Magee had tainted the jury by alleging Simmons had engaged in a homosexual act while in prison.

Magee later explained the judge’s ruling to mean that the allegation was considered “uncharged misconduct” that would make it difficult for a jury to render a fair and impartial verdict.

Several hours earlier, Register had been equally upset when he was informed that the prosecution wanted to present newly discovered DNA evidence purportedly linking his client to the gun that killed Mark Boutin, the victim in the case.

This new evidence — a report from the Acadiana Crime Lab — was discovered about two hours after the prosecution had rested its case, and soon after Simmons had taken the stand in his own defense.

During his testimony, Simmons said he had never touched the gun.

Register blasted both the prosecutor and investigators for their last-minute discovery and questioned why the lead investigator had not pursued the report earlier.

Register said he would call for a mistrial if the new evidence was admitted because it would undermine his client’s case, which had been partially built around the fact that there had been no physical evidence connecting Simmons to the gun.

The gun was discovered by Lafayette city police during a search of a vehicle in Lafayette about three days after the shooting. Four men, one of whom was Simmons, were detained and questioned about the gun.

After more than an hour, Simmons claimed ownership. On the way to the jail, Simmons recanted, saying he only claimed the gun to protect the people he was with at the time.

On the stand, Simmons testified that he was pressured to “take the charge” by others who had worse criminal records than him.

Simmons said he had no knowledge at the time that the gun had been used in a homicide. The Acadiana Crime Lab later matched the gun to spent shell casings at the crime scene in Carencro.

The Lafayette Police Department sent the gun to the crime lab for testing in July 2009. The lab returned the results in March.

Carencro Police Capt. Ronnie Richard, the lead investigator, testified that his department never received those results, although he admitted to not following up with either the Lafayette Police Department or the crime lab.

Richard said he assumed the results were negative because he never heard back from the lab.

While questioning Richard, Register asked him if he was asking the court to admit the evidence late “because you didn’t do your job?”

Register called the mistake a product of “incompetence.”

Register also questioned Carencro Assistant Chief Dondi Hardin about whether his department should have followed up sooner about the report.

“In hindsight, I would agree with that,” Hardin said.

Ultimately, the argument became a non-issue when Magee opted to withdraw his motion after speaking with a lab official about the report, which apparently was not as conclusive as investigators initially believed.

Still, it made for interesting courtroom debate.

Jason Brown covers police and courts in The Advocate Acadiana bureau. He can be reached at jbrown@theadvocate.com.