The movie had a giant plot hole

The arrest scene was a giant plot hole. Ingrid killed her boyfriend in a way that was very difficult to prove and would have to be dealt with advanced forensics and good detective work before she was even taken in as a person of interest. And even if she was ''suspected'' she would first be taken for questioning before ever being arrested. She used a combination of a poisonous flower and a potency enhancing drug which she rubbed all over areas he would touch and on forks and knives. His death would also be rather slow and could appear like he succumbed to an unknown ailment etc.

In the film they arrest her seemingly a few days after he died and say '''You're being charged with murder'' and drag her off to the police station with a quickie court proceeding where she is found ''guilty''. That wouldn't have happened unless she shot him out in the open street at 4 P.M lol.