Motive - Season 3 Episode 1 -

The killer: Derek Caster. The victim: London Montgomery, the grown daughter of wealthy industrialist, Neville Montgomery. Six months out of drug rehab and seemingly clean during that time, London is found dead from being poisoned on what was the night of her birthday party joint drug rehab facility fundraiser. Betty suspects that the drug was purposefully given to London as what she believed was cocaine. Oscar recuses himself from the case when he learns that the last person to text London before she died was his father, Franco Vega, who has a thing for younger women ...