It is mentioned in Parents' Day that he knows the mayor.
Season 4In Eye of the Tiger, Danny warns Liberty that if their father comes home and sees her and J.T. together, he will kill them. Liberty designates Danny as the "watch dog", but he fails to cover for her. When Harold arrives home from work, he walks into his yard to see J.T. and Liberty kissing in the hot tub. He angrily tells J.T. to go home, and against Liberty's protests that J.T. is one of her oldest friends, Harold reminds her that he is also a teenage boy. He tells Liberty that if she wants to see J.T. again, she needs to wait until she's twenty. Later, on another day, when Harold asks Danny where Liberty is, Danny this time lies for Liberty and says she is at a student council meeting at school, while she is really talking to J.T. in the yard.
In the episode Turned Out (2), they find out that Liberty is pregnant and J.T. is the father of their first grandchild. He is completely pissed and wants Liberty to stay with them at home with J.T. out of the picture, but Liberty refuses and begins to pack her bags. Later, at the hospital, he is with there his wife and Liberty to visit J.T. while he is getting his stomach pumped.
In Together Forever, he is in the delivery room after Liberty gives birth to her baby.In Total Eclipse Of The Heart, he and his wife give Liberty the news that the baby and his adoptive parents are moving to Seattle. He later yells at Liberty after she fails her Chemistry exam, but leaves to see a play with his wife. Danny reveals he also grounds Liberty for getting drunk and breaking a mirror that was in their living room.
In We Built This City, he attends Liberty's graduation. When Liberty's name is called to receive her diploma, he smiles proudly at her.