LOS ANGELES (October 21, 2012)—Fans of scary movies are still into "Paranormal Activity," although the horror franchise looks as though it's starting to run out of steam at the box office.

According to studio estimates released Sunday, "Paranormal Activity 4" debuted at No. 1 with $30.2 million, a big drop from the $40 million and $50 million opening weekends of the last two installments.

The franchise about supernatural sightings has been a Halloween perennial since the original "Paranormal Activity" became a low-budget sensation in 2009.

"Paranormal Activity 2" opened with $40.7 million two years ago, while last year's "Paranormal Activity 3" launched with $52.6 million last year.

This weekend's other new wide release, Tyler Perry's crime thriller "Alex Cross," had a so-so opening, taking in $11.8 million to finish at No. 5.