The legal saga regarding the Philadelphia Catholic Church sex-abuse scandal continued Monday as a prosecutor said in her opening statement she would prove that a priest and a Catholic school teacher sexually assaulted the same middle-school altar server in separate incidents.

Defendants Bernard Shero and the Rev. Charles Engelhardt had their cases severed from the trial of Monsignor William J. Lynn, the first Catholic Church official in the country to be charged with harming sexual-abuse victims whose abuse he was responsible for investigating.

While Lynn’s trial proceeded separately, Engelhardt and Shero’s trial will involve some of the same set of facts. Engelhardt and Shero are accused of abusing the same boy who Lynn was convicted of endangering his welfare. D.G. testified that, at the age of 10, when he was an altar server at St. Jerome Parish in Philadelphia, he was not warned that defrocked priest Edward V. Avery was a danger to him. Avery pled guilty to abusing D.G., and he was sentenced to 30 to 60 months in prison.

The Legal is not naming the known and alleged victims.

Prosecutor Evangela Manos said that Avery would testify as a prosecution witness and that Avery’s testimony would corroborate D.G.’s testimony. Engelhardt is charged with conspiring with Avery to both abuse D.G.

Sexual predators “choose their prey wisely,” Manos argued to the jury. “They know who to choose. They know who won’t tell.”

D.G., when entrusted to the church by his mother, a nurse, and his father, a police sergeant, was abused by “not only one but three of those entrusted with his care,” Manos said.

Both of the defense attorneys portrayed D.G.’s stories regarding their clients as changeable and even fantastical, while the prosecution said that D.G.’s stories changed because he was struggling with drug addiction.

The defense attorneys also told the jury that D.G., who is represented by Slade McLaughlin, was motivated to lie in order to seek recovery in the tort system.

Engelhardt’s defense attorney, Michael McGovern, said D.G.’s first report was that he was abused by eight priests and one teacher, and that D.G. changed his story on how many times Engelhardt allegedly abused him.

The sacristy where the abuse allegedly took place was a tiny room with four doors, including a door that connected to a parish school, McGovern said. The defense attorney questioned how D.G.’s abuse could have taken place for five hours when a Mass also was served after the Mass that Engelhardt and D.G. served together.

Shero’s defense attorney, Burton Rose, said D.G.’s first report of his abuse by Shero was that it was in a classroom; then that it was a violent attack in Shero’s car while parked in an apartment parking lot, and that Shero punched D.G. and wrapped a seatbelt around his neck; and then, finally in the last iteration of events, that the abuse was in Shero’s car in Pennypack Park.

D.G. was abused in his fifth grade year, first by Engelhardt and then by Avery, Manos said.

D.G. was abused in his sixth grade year by Shero, Manos said.

Shero was D.G.’s homeroom teacher and language arts teacher, Rose said.

D.G. started using drugs like marijuana and heroin to help him forget about the abuse that had been inflicted upon him, Manos said.

But Rose argued that D.G.’s grades stayed the same and he stayed involved in extracurriculars and that it was only in high school that he got involved in drugs.

The stories of sexual abuse were how D.G. “found a way to explain away his own bad choices in life,” Rose said.

D.G. first revealed the abuse to a drug counselor who referred him to an Archdiocese of Philadelphia hotline for sex-abuse victims, Manos said.

When D.G. called the hotline, his father did not want him to talk to church social workers instead of officials in the criminal justice system, and D.G. got high between the time he made the report and the time that church officials drove to his home, Manos said. He does not remember what he told the church officials in that interview, Manos said.

Philadelphia Court of Common Pleas Judge Ellen Ceisler is presiding over the trial.

Before opening statements were made, Engelhardt was arraigned, in error, on the charge of raping a child. Shero was about to be arraigned, in error, on a conspiracy charge.

Engelhardt pled not guilty when he was arraigned, accurately, on charges of involuntary deviate sexual intercourse, endangering the welfare of a child, corruption of minors, indecent assault on a person less than 13 years old and conspiracy.

Shero pled not guilty when he was arraigned on charges of rape of a child, involuntary deviate sexual intercourse, endangering the welfare of a child, corruption of minors and indecent assault of a person less than 18 years old.

When Shero tried to commit suicide after being arrested and left a note apologizing for the shame and ridicule such accusations would bring upon his family, Rose said his client tried to take his own life, not because of guilt, but because of how vile society views persons charged with child sexual abuse.

Shero always has faced taunting, including by the schoolchildren he taught, because he is legally blind in one eye, and he has severe visual limitations in his other eye as well, Rose said.

Engelhardt is a member of the teaching order Oblates of St. Francis de Sales, McGovern said.

A pediatrician also is going to testify on D.G.’s behalf, Manos said.

Amaris Elliott-Engel can be contacted at 215-557-2354 or aelliott-engel@alm.com. Follow her on Twitter @AmarisTLI.