Why was GA in scrubs when he was interrogated? He hadn't been employed for months, least of all in a health care setting. There was 0 reason to be wearing scrubs.
Amaro had a job interview a day after the murders for a nursing position (or so he claims).

25-FL v. Amato: Witness Testimony
Sloan Young, Arthur Rubart, Nicholas Stewart, Geraldine Blay, Rodney Funke, Erika Johannsen, Sam Cores & Jason Amato testify in the trial of Grant Amato.

Law&Crime - witness testimony - Erica Johansson describes Grant Amato job interview
Timestamp 1:40