This can be a tough boss, but again it's all about finding the right android.
Starch is your android of choice here. The laser is good at cutting though Justice's missiles, while the micro missiles avoid his shields, hitting him in the flanks for good damage.
Justice only has 3 sections.
Start off by hitting him head on with your laser, avoiding his beam when he charges it. He will soon drop laser posts around the map. With other androids (except maybe Cactus) these where a problem, but with Starch, I kept focusing on the orbs that spawned, and the laser took out a few of the posts without me even thinking about it. I guess this would be a good opportunity to also get the prison break achievement too.
As previously mentioned, Justice will start spawning orbs that will attach a tether to you and try to pull you into the laser fences, so you should prioritise these. They are quickly dispatched however, with a quick sweep of the laser.
The second part has Justice charging around firing missiles at you. Simply focusing your laser on Justice will cut down a lot of these and do damage to him atthe same time. Press
occasionally when you're close enough to unleash some micro missiles for good damage, and mop up any missed missiles that may hit you, with the laser.
Part 3 is the hardest part, you'll face a combination of the orbs, missiles and lasers from Justice as well as more laser fence drops. Avoid the lasers and keep focusing on Justice with all you have, dispatching micro missiles when available and picking up the speed/damage boost power ups when they drop.