PITTSBURGH — A Pittsburgh man goes on trial today on charges of killing three police officers responding to a domestic dispute call at his mother’s house in April 2009.

Authorities believe Richard Poplawski laid in wait after the call and then killed city officers Paul Sciullo II, Stephen Mayhle and Eric Kelly during a three-hour standoff.

Poplawski’s mother told a 911 operator her son had a weapon but that information wasn’t relayed to police, officials said.

The defense has dropped plans to pursue an insanity defense, but lawyers still expect to raise mental-health issues at trial.

The trial will take place at the Allegheny County Courthouse with jurors brought in from central Pennsylvania because of the pretrial publicity. A video feed of the testimony will be played live in an overflow room at the courthouse, given the intense interest in the case.

Cameras are typically banned in Pennsylvania courtrooms, in contrast to several other states that sometimes broadcast high-profile trials to the public.

Judge Jeffrey Manning agreed to reserve seats in his courtroom for relatives of the officers, the suspect and trial witnesses. But police union officials said they were not encouraging their members to turn out in force.

“We want the trial to progress without anyone saying that we interfered,” Fraternal Order of Police president Dan O’Hara told a Pittsburgh newspaper. “I don’t want a mistrial declared.” The 12 jurors and six alternates come from Dauphin County.

Authorities allege that Poplawski fired at nine other officers during the standoff, wounding one of them. Prosecutors will seek the death penalty if he is convicted of first-degree murder.

The defense is fighting attempts by prosecutors to use a clip of comments Poplawski made on an online radio show in 2007, in which he allegedly vowed to “make the history books” someday by killing an ex-girlfriend, her family members, pets, neighbors and two police officers, a Pittsburgh newspaper reported.