She said the pair would usually arrive at the gym at the same time but Werahiko otherwise kept to himself.
"When Michael came to the gym he just did his workout, he didn't really speak to anyone else. People tell me they used to be talking in the changing room.
"He had told me he was an arts student at UCOL."
Ms Lock said after Werahiko was arrested for a bail breach, Mr Round helped him by collecting items from home.
The day of his release from prison, May 16 last year, Werahiko was met at the Wanganui bus station by Mr Round, she said.
"[Mr Round] had told me that he was going to pick Michael up that afternoon, and Derek said he was going to stay at his place for a couple of days while he got everything sorted at his flat," Ms Lock said. "And he had said 'I would probably be back at the gym tomorrow with Michael'."
The next day Mr Round, 77, was found dead in his Campbell St home, and five days later Werahiko was charged with his murder.
Wanganui mayor Annette Main also knew Mr Round and said he was supportive of and enthusiastic about the city.
"He had already managed to take part in lots of things. ... "Sometimes people move to a small town and it takes them a long time to assimilate into it and to work out where they would spend their time. But he seemed to straight away say 'right, I'm going to get into this'. It's quite unusual, especially for an older person."
Ms Main said Mr Round never mentioned other friends in Wanganui but said he was interesting to talk to and always willing to engage in a conversation. "I guess that happened to him a lot - that he got involved with people."