(CNN)-- A police officer who investigated after a woman reported then-Penn State coach Jerry Sandusky had showered with her son in 1998, testified Thursday in Sandusky's trial he felt charges should have been filed against him then, although prosecutors at the time did not agree.
Ronald Schreffler, a former Penn State police investigator who now works for the Department of Homeland Security, said he was among officers hiding in the woman's home when she confronted Sandusky about her suspicions regarding alleged inappropriate behavior with her son, identified as Alleged Victim 6. He testified he heard Sandusky tell her: "I wish I could ask forgiveness. I know I can't get it from you. I wish I were dead."
More of Sandusky's alleged victims testified Thursday, including a man identified as Alleged Victim 3, who said Sandusky would touch him inappropriately during showers and overnight stays at the former Penn State coach's home.
Sandusky, longtime defensive coordinator for the Nittany Lions, faces 52 counts tied to what prosecutors say was his systematic abuse of at least 10 boys over a span of 15 years. Now 68, Sandusky has been under house arrest in the days leading up to his trial. He has pleaded not guilty and has maintained his contact with children was not sexual.
Judge John Cleland said Thursday he expects the commonwealth of Pennsylvania to conclude its case against Sandusky Thursday afternoon.
Alleged Victim 3 -- CNN generally does not identify alleged victims of sexual assault -- testified Thursday that he was part of Second Mile, the charity founded by Sandusky, and that he stayed overnight at Sandusky's home "more than 50 times." Sandusky often came downstairs where he was sleeping, he said.
"He would ask me why I would want to sleep with all my clothes on, so eventually I'd be stripped down to my underwear," said the man, now 25. "He'd jump into bed with me, start tickling me, blowing on my stomach and pelvis. He would also, at times, touch my penis."
Asked if he told Sandusky to stop, he said, "No. I was enjoying the things I was getting too much," referencing trips to football games and favors from Sandusky. "He made me feel like I was part of something, like a family," he said. "He gave me things that I had never had before. ... I loved him."
He said he never told anyone about his experiences. Eventually, he said, he was sent to group homes, then foster care.
"He never contacted me," he said of Sandusky, saying he was angry "because he could just forget about me, like I was nothing, after all that."
By 1999, as a 12-year-old, he testified he was uncomfortable with the contact. "I would roll over (in bed) and try to get away from him," he said. "That's pretty much where it would stop; I wouldn't let it go any further."
He said he also showered with Sandusky after workouts, and that Sandusky would help wash him and "grab my shoulders and give me a big hug, both with my back to him and with my front to him."
Alleged Victim 6 testified about the 1998 incident, when he was 11, that triggered a police investigation. After working out with Sandusky at Penn State, he told jurors he recalled feeling uncomfortable while showering with Sandusky.
He said that when both were naked, he started to shower across the room from Sandusky. "I didn't want to be right next to him in the shower. I felt really awkward with that situation." But, he said, Sandusky told him to come over next to him, then began tickling him.
"I believe at one point he grabbed me from behind and gave me a big bear hug. ... He said, 'I'm going to squeeze your guts out.' I remember seeing his chest hair right in my face, and thinking, 'This is icky.' "
He remembered Sandusky helped wash him and told him, " 'Let me help you with your back, where you can't reach.' ... It was just escalating, the uncomfortableness of it."
He testified that he cannot remember anything, even the trip home, after Sandusky lifted him up to the shower head to get the shampoo out of his hair. "It's just kind of black," he said.
When he got home, he said he told his mother: "'By the way, if you see my hair is wet, it's because we took a shower," adding, "She knew who I took a shower with. I told her bits and pieces, but not about everything that happened."
His mother, he testified, called police.
Schreffler testified he interviewed the boy and, after consulting with the district attorney's office, asked the mother to invite Sandusky to her home twice with authorities hiding in another room. During the second meeting, he heard Sandusky make the statement about forgiveness, he said.
Schreffler said he talked with Sandusky as well. The then-coach acknowledged showering with other boys but said nothing sexual had taken place, he said. Sandusky "stated that he did think it was maybe inappropriate," Schreffler said. "He wouldn't do it again. ... He used the term 'bad judgment.'"
Asked if any charges were filed, Schreffler said, "No. I felt there should be some charges, something, but the DA didn't go for that."
"There was a missed opportunity in 1998, an opportunity that wasn't just missed by one person -- it was missed by multiple people," Howard Janet, an attorney representing Alleged Victim 6, told reporters afterward. He called it "saddening" and said it adds to the pain his client experienced.
Under cross-examination, Alleged Victim 6 acknowledged he maintained contact with Sandusky afterward, attending football games with him, meeting him and his wife for lunch and at one point borrowing his car. He also said he sent Sandusky holiday greetings, including one saying, "I'm glad God has placed you in my life." The two never again showered together, however, he said.
Alleged Victim 3 was asked by defense attorney Joe Amendola about his grand jury testimony, in which he said he had stayed at the Sandusky home more than 25 times.
"But then I thought about it more," the man said. "I've tried to block this out of my brain."
Both alleged victims Thursday acknowledged they had hired civil attorneys, but said they had not paid them anything.
Under questioning from Amendola, Schreffler looked at a transcript of his May 1998 interview with Alleged Victim 6 and testified the boy insisted Sandusky never touched him in an inappropriate place or asked the boy to touch his "private parts."
Jurors on Wednesday heard graphic testimony from three alleged victims, the father of a then-graduate assistant who said he witnessed Sandusky raping a boy, and a janitor who testified that he saw two pairs of legs in a shower, believed to be the ex-coach and a child.
In opening statements, defense lawyer Amendola suggested his client would take the stand and say he routinely "got showers with kids" after working out.
The case has raised questions about Penn State's response to allegations, with some claiming the school put its reputation ahead of protecting potential child victims.