Mrs. Bates poisoned this guy she was involved with when she found out he was married. Then took a helping of the same stuff herself.
12 seconds sound clip from the Psycho (1960) movie soundboard.
You can hear this line at 01:24:23 in the Blu-ray version of the movie.
Quote context
[...]
- And he didn't come back? He didn't see the mother?
- Yes.
- Norman Bates' mother has been dead and buried in Green Lawn Cemetery for the past 10 years.
- I helped Norman pick out the dress she was buried in. Periwinkle blue.
- It ain't only local history, Sam. It's the only case of murder and suicide on Fairvale ledgers.
- Strychnine. Ugly way to die.
- Norman found them dead together. In bed.
- You mean that old woman I saw sitting in the window out there wasn't Bates' mother?
- Now, wait a minute, Sam. Are you sure you saw an old woman?
[...]