Bellefonte, Pennsylvania (CNN) -- About 100 more potential jurors showed up for questioning Wednesday as attorneys continued to select a jury for the trial of Jerry Sandusky, the former Penn State assistant football coach charged with child rape.
Nine jurors have already been chosen for the panel. The five men and four women include an engineer, a high school teacher, a doctor, a retired Penn State professor, a retired school bus driver and a Penn State student who works part-time for the university's athletic department.
About 220 potential jurors reported for duty Tuesday, after the court whittled the number to about 600 based on answers to questionnaires sent to prospective jurors' homes. Of those, about half were sent home and asked to return Wednesday.
Jury selection begins in Sandusky trial Sandusky, 68, has been under house arrest since being charged with sexually abusing 10 boys for at least 15 years. Prosecutors say he met some of his accusers through Second Mile, a charity he created for underprivileged children. He has pleaded not guilty to the charges.
Letters written by Sandusky to one of his alleged victims, identified only as Victim 4, can be described as love letters, a source familiar with the case told CNN on Wednesday. One letter describes love between a man and a boy, the source said.
The letters are expected to be entered into evidence during the trial, two sources with knowledge of the case said, and could be incriminating evidence against him.
However, the letters, as first reported by ABC News, may be given a completely different interpretation by the defense. They're expected to argue the letters and notes that Sandusky sent are benign and illustrate his love for the children he's helped over the years through Second Mile, according to a source familiar with the case who asked not to be named.
ABC News reported late Tuesday that Sandusky supposedly wrote love letters to Victim 4. They will be read into testimony, ABC said.
The attorney for Victim 4, Ben Andreozzi, said Tuesday that he expects letters from Sandusky to his client will be introduced at the trial, but he declined to comment on their content.
Gifts that Sandusky allegedly gave to Victim 4, who is now a 28-year-old man, may also be introduced as evidence by prosecutors, according to a source close to the case. Those gifts could include golf clubs and football jerseys, a source said.
A source close to another alleged victim, Victim 1, said that Victim 1 received birthday cards and notes from Sandusky, but that they were not sexually explicit in nature. They included statements such as, "I love you," but did not contain anything overtly sexual, that source said.
The prospective jurors were quizzed Tuesday and Wednesday about their relationships with Penn State, local law enforcement and Second Mile, and whether they had contributed to any of those entities. Several reported knowing Sandusky or his wife, while others said they had volunteered at Second Mile.
Many were current or former Penn State employees or financial contributors to the university. Some said their jobs require them by law to report suspected sexual abuse cases. When answering questions, prospective jurors were asked to consider not only their own status, but also that of relatives.
Opening statements are expected to begin Monday, Judge John Cleland said, and the trial is likely to last about three weeks. Twelve jurors and four alternates will eventually be selected.
Prosecutors plan to call more than 50 witnesses during the trial, and the defense plans to call about 100, including Jay and Sue Paterno, coach Joe Paterno's son and widow; former graduate student Mike McQueary; his father, John; and former university President Graham Spanier, among others. Defense attorneys said Wednesday their list will also include seven Sandusky family members.
Authorities allege that Sandusky abused some of the boys on the Penn State campus. The case has shaken the university, raised questions about its response to the allegations and drawn criticism from those who claim Penn State put its reputation ahead of protecting potential child victims.
Spanier and iconic head football coach Paterno lost their jobs soon after Sandusky's arrest amid criticism that they did not adequately handle the matter when allegations involving Sandusky arose years earlier. Paterno died of complications from lung cancer in January.
McQueary, the former graduate student, is considered to be a key witness in the Sandusky case. He has testified that he alerted Paterno in 2002 that he'd seen what appeared to be Sandusky sexually assaulting a boy in a shower in Penn State's athletic facilities, an allegation that authorities didn't learn of until years later.
Paterno apparently told the university's athletic director, Tim Curley, but no one notified police. Curley and Gary Schultz, Penn State's senior vice president for finance and business, are now facing felony charges of perjury and failing to report the allegations to authorities.
Prosecutors said later that the McQueary incident took place about a year earlier than was originally alleged, causing defense attorneys for Curley and Schultz to argue that one of the charges should now be dropped. Both of them have pleaded not guilty, and their attorneys have said that prosecutors "charged this case before (they) knew the facts."
The prosecution is preparing witnesses for their testimony next week, several sources close to the case said Tuesday. Victim 4 is expected to testify first, with Victim 1, who started the investigation by coming forward in 2008 and alleging years of abuse, to follow, the sources said.
McQueary and his father were told to be in town and ready to testify next Wednesday or Thursday, one of the sources said.
Cleland told members of the jury pool that jurors in the case will not be sequestered, saying he will trust them not to read newspapers or follow the case online.
As jury selection in the case began Tuesday, Penn State released a statement, saying, "The acts that Jerry Sandusky is accused of committing are horrible and if proven true, deserve punishment."
The university said it would not comment on the specifics of the legal case, but said it hopes that the trial "provides answers we are all seeking" and that "the legal process will start to bring closure to the alleged victims and families whose lives have been irrevocably impacted and that they can begin the healing process."
Several of Sandusky's alleged victims, including Victim 4, asked a judge to protect their identities at trial. However, Cleland ruled Monday that the alleged victims' identities may not be concealed during the trial, although they will be protected through the jury selection process. CNN generally does not identify alleged victims of sexual assault.
In interviews after his arrest, Sandusky acknowledged showering and "horsing around" with boys, but denied being sexually attracted to them.
CNN's Susan Candiotti, Ross Levitt and Dana Garrett, CNN contributor Sara Ganim and In Session's Lena Jakobsson contributed to this report.