Sergeant Jack Tierney was a character in the film Friday the 13th.
During a late night storm in the summer of 1979, the patrolling Tierney happens upon Steve Christy stranded in the middle of the road, his truck having broken down. Stopping nearby, Tierney offers to drive Steve to Camp Crystal Lake, help which Steve gladly accepts.
While driving to the campgrounds, Tierney makes small talk with Steve, mentioning how its Friday the 13th and a full moon, a bad combination which can make people act crazy, insane, and nuts. As Steve scoffs at this old superstition, Tierney gets a call from dispatch reporting a car accident with possible fatalities/casualities a short distance away. Needing to go to the scene, Tierney drops Steve off a short distance from the lake and heads to the crash site.
When Alice Hardy, the sole survivor of Pamela Voorhees's killing spree at Camp Crystal Lake, wakes up in the hospital the day after the brutal murders, Tierney visits her. Tierney informs Alice that all the other camp employees are dead and, when Alice questions him as to whether Jason Voorhees was dead too, Tierney claims that none of his men found any evidence of a boy out on the lake at all, where Alice claims Jason attacked and dragged her. This leaves Alice with the impression that Jason was still out there. 
- Friday the 13th (1980)
- Friday the 13th (1987)
- ↑ Friday the 13th