The relief detail didn't show up.
2 seconds sound clip from the The Big Heat (1953) movie soundboard.
You can hear this line at 01:15:46.430 in the Blu-ray version of the movie.
Quote context
[...]
- Vince must hate her insides. He never could take losing or being pressured.
- He's got to take it. If she dies, the letter goes to the newspapers.
- You know, I almost killed her an hour ago. I should have.
- Must be for me. I told them downstairs I was up here.
- The relief detail didn't show up.
- I called the police station. They said they weren't coming anymore.
- Keep the door locked till Al gets home. I'll be there in an hour.
- Okay, mac. Get 'em up high. Upstairs, mac, nice and easy now.
- Stop, Dave. Hold it, Mark. Come on, hold it.
[...]

 Phantom of the Opera (1943)
 Phantom of the Opera (1943)  Scooby-Doo, Where Are You! (1969)
 Scooby-Doo, Where Are You! (1969)  Halloween III: Season of the Witch (1982)
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 Knight Rider (1982)  Garfield's Halloween Adventure (1985)
 Garfield's Halloween Adventure (1985)