From The TimeSplitters Wiki

The lasergun;s first and only appearance has been in Timesplitters 2, where it is one of the guns in the Robot Factory story level and various other weapon sets. The lasergun's primary fire is a laser, which can be charged up when the fire button is held down. The lasergun also has a shield set to the alternate fire button, much like the Scifi Sniper in TSFP. The shield will protect the upper part of the body from the front, but leg and back attacks will still do damage. When crouching, the head is not protected by the shield.

Noise Glitch

In TS2, there are many glitches. One is the lasergun's sound glitch. If a player is charging the lasergun and gets killed, the charging sound may get stuck, just like the minigun's. The lasergun sound gets stuck in a specific spot, so the closer you are to that spot the louder it is. It will go away only after the battle is over.