Hardline Pro Mechanics in MW3?

If you're using Hardline Pro, if you get a single assist and die, then get a second assist later, together the two will count as a single kill towards your streaks.

Further testing today has shown that the assist count is across deaths regardless of the strike package, although the streak count resets every death unless you are using Support.

Although you get credit for an assist each time someone kills a player you tagged with your Recon Drone, those assists do not count for the purposes of Hardline Pro.

It makes your assits count towards your kill streak. 2 assists = 1 kill strike point, It also reduces the amount of deaths needed to reach your death streak like in MW2. Also the support package is the only kill streak package that allows you to keep the kills gained from previous spawns. The stike and specialist packages are reset each death you get.