Sharon Baxter, a colleague of Mulholland, gave evidence that she saw her "very brutally and very roughly" inject John Gethings (77) with an unprescribed sedative.
Ms Baxter was working with Mulholland in the Curragh ward at Naas General Hospital on the night of March 1st and said Mr Gethings was under Mulholland's care. He was restless and agitated and she heard him call out numerous times that night. At one stage she heard him call out: "I am dying, I am dying."
At 2am she heard Mulholland say that she had to give the patient something "to shut him up". She told Ms Baxter that she would show her the patient's prescription chart later before she quickly drew the sedative, Serenase, into a syringe and went to Mr Gethings.
Ms Baxter followed and went to the patient where she said she tried to reassure him and tell him he was going to get "a little injection" and that he would feel a "pinch", when she heard the man "let out a roar".
She looked up to see Mulholland giving him an intra-muscular injection in the buttock "very roughly and very brutally".
"She drew her arm back a lot more than was required, so she gave him the injection with a lot of force," Ms Baxter told the jury.
As Mulholland withdrew the needle, Ms Baxter said she saw that Mulholland had used a 16-gauge white needle which she explained was not the correct needle to use for an intra muscular injection. The correct needle was a 23-gauge blue which she said was a lot smaller.
Ms Baxter told the jury she later checked Mr Gethings chart and saw that he had been prescribed Serenase by a doctor but it had been prescribed in a once nightly tablet form and not via an intra-muscular injection.
She also saw that Mulholland had given him this Serenase tablet at 10.30pm that night.
Sinéad Noonan-Noctor told the jury she saw Mulholland "roughly dart" an injection into Séamus Doherty (80) before throwing water over him and threatening him.
She said Mr Doherty was under Mulholland's care that night and he had been calling out aloud and shouting for help.
At about 4am and 5am, Mulholland said she was going to check on him and came back shortly to say she was going to give him Serenase to calm him down.
Ms Noonan-Noctor agreed to check the drugs for her and waited for her to return with them but she then saw Mulholland walk past her with the Serenase and go over to Mr Doherty's bed.
She said she followed and saw Mulholland draw up the drug quickly and push Mr Doherty on to his left side before she "very roughly darted" the needle into his right buttock using a 16-gauge white needle.
The jury also heard evidence from Dr Hamid Mushtaq that he prescribed the intra-muscular injection of Serenase to Mr Doherty on the night shift of July 3rd, 2003, after he was bleeped because the patient was hitting and kicking staff and was considered a danger to himself and others.
Dr Mushtaq said he told Mr Doherty's doctor, Dr Michael Durrity, the next day that he had given the patient Serenase the previous night and that Dr Durrity said Mr Doherty was not to be given the drug so Dr Mushtaq wrote "not for Serenase" on the patient's chart.