Seven officers were in the courtroom for much of the time Tuesday during a suppression hearing for Deangelo Ross.
He wore a net that covered his head down to his neck.
Authorities said Ross is prone to spit on officers and attack them.
He is facing charges of aggravated sexual battery and indecent exposure in an incident Nov. 24, 2012.
Family members said they found a three-year-old on top of Ross on a couch, with Ross with his hand on his bottom. Both had their pants down.
Ross told police that the three-year-old woke him up, then pulled his (Ross's) pants down before taking off his own pants.
He claimed the child told him "We ain't going to get caught. It's OK."
Police said family members advised that Ross "had molested children before."
S. McClarty, the grandmother of Ross, said he had always lived with her. She said he was quiet when on his medication for mental health issues, but can go off when he is not. She said she would always know when he was off his medication, saying he would "mouth off. He might go out and cuss out the neighbors."
The witness said prior to the incident he had stopped taking pills, so he was getting shots from Fortwood Center. She said she advised that stronger doses were needed, but was told he would have to come in later for an appointment. She said she advised that he needed the shots as soon as possible.
Ms. McClarty said he has a low IQ, but did alright in regular school until around the ninth or 10th grade when he started having problems. She said he was moved to the Dawn School after he fought with and hit a teacher.
She said he receives SSI checks, and she deposits the checks and gives him the money. She said he had started using the money to buy marijuana and alcohol.
Det. Robert Bell said Ross appeared to understand the questions he asked him.
He said he was able to give his Social Security number. The detective said, "That's almost a rarity."
The defense is seeking to have statements he made suppressed based on the lack of a Miranda warning and his competency.
Police said he did not give a confession.