9mm Mayhem is a side mission in Grand Theft Auto: Liberty City Stories. To start this mission get on the Freeway behind Woody's Topless Bar in the Red Light District. This is required for 100%. And after completion you can return to the bike and try to beat your best score.
In this mission you have to eliminate more than 10 targets in under 3 minutes and 30 seconds. You receive 3 adrenaline pills. For this you will get a MAC-10 and a driver on a Freeway. Also you will get a damage meter, if it fills up completely you will fail the mission. And instead of dying you just respawn back to the starting point.
The first two targets are PCJ 600s. They don't have gunman so you can destroy them without trouble. First you get $5 for the first one and $20 for the second one. The next two targets also don't have protection. They are two Yardie Lobos. For the third one you get $45, and then $80 for the next. The fifth target is when the gunman start coming. The next two are Stingers with one MP5 gunman. For the fifth you get $125.
After destroying the sixth target you will get $180. Then the next two are Bobcats with one MP5 gunman. After disposing of the seventh you will receive $245 and $320 for the next. Target number nine is a Bobcat with an AK-47 gunman. Destroying this will reward you with $405. The next one is a Patriot with an M4 gunman. After eliminating this one you will get $500.
Number eleven and twelve are the same as number 10. Number eleven will give you $605, and number twelve will give you $720. Number thirteen will probably be the last one due to the lack of time. But this one is a Patriot with a Shotgun gunman with a reward of $845.