Duncan Stinson

Duncan Stinson is the father of Emily Stinson, whom he switched with Sarah O'Brien when they were two days old.

History
Melinda and Duncan were called into the practice when it was discovered that their baby had been switched with Beth and Greg O'Brien's baby when they were infants. Duncan in particular was upset when they learned that their daughter had an incurable genetic disorder, because they'd spent thousands of dollars on fertility treatments to get pregnant.

After looking through staff schedules and visitor logs, they doctors determined that Duncan had been the one to switch the girls after Emily had a seizure when she was two days old and he was arrested. Melinda was upset at him for having given away her baby. She'd had a c-section with complications, meaning she was unaware of anything being wrong with the baby after she was born. After Duncan's arrest, the girls were switched back.

Romantic
He is married to Melinda Stinson. However, after learning that he'd switched their baby with another one in the nursery, Melinda said he wasn't her husband anymore, indicating that she'd be pursuing divorce.

Familial
Melinda and Duncan wanted a baby, but were unable to conceive on their own, so they enlisted the help of Naomi Bennett, who helped the conceive. When their baby was two days old, she had a seizure, so Duncan switched the two girls. Melinda unknowingly raised the O'Briens' baby for nine months until the switch was discovered and the girls were switched back.