A liar from Wales

A man from Wales had stolen £40000 from his elderly neighbor. The man must had to go to a   court, but he didn't hadn't want to go because he had   suffered from an illnesses. He couldn't move his legs or arms.
The man was a lair. Police had found a video where ha had been walking and driving a car, but the man told them that it was a mistake.  He couldn't do it.

Hello Alina, 

After the first time we mention a person it is normal to use a pronoun (he, she) to refer to them -

A man from Wales.... he was a liar.

A Liar from Wales

A man from Wales had stolen £40000 from his elderly neighbor. The man must He had to go to a court, but hadn't wanted to go because he had suffered from illnesses... He said he couldn't move his legs or arms.
The man was a liar. Police had found a video where he had been seen walking and driving a car, but the man told he said that it was a mistaken identity because he couldn't do it.