Officer Richard Kern is charged with the assault. Officers Andrew Morales and Alex Cruz are standing on trial for covering it up.
It happened at a Prospect Park subway station, the officers were attempting to arrest Mineo for smoking pot, handcuffing him on the ground.
"I see Richard Kern has a metal retractable baton," Maloney testified.
"What is he doing with it?" the prosecutors asked.
"I saw Richard Kern had it placed on Michael Mineo's buttocks," Maloney said.
With that six inch baton, which is commonly carried by officers, Maloney says pressure was being applied.
"It went left to right and into Michael Mineo's but, it was covered by clothing, but one half to one inch was out of my sight," he said.
It wasn't until later that Mineo, who previously testified about the attack, showed police officers that he was bleeding.
"Michael Mineo takes his hands and slid them to the left and exposes his hands and there is blood on them. He states that he is bleeding," Maloney testified.
Richard Kern's attorney countered.
"Did you hear him scream out in pain?" he asked.
"No," Maloney said.
"Did you see any officers pull his pants down?" the attorney, John Patton, asked.
"No," Maloney replied.
"Did you hear Michael Mineo say to anyone no, no, no?" Patton asked.
"No. I didn't," Maloney said.
Defense attorneys seized on Maloney's own admission that he did not immediately call a supervisor, which is normal procedure when someone is injured. He didn't come forward until later.
One blow to the defense came with testimony that showed Mineo's DNA was found on the metal baton.