When I made the switch over to 4th Edition, I had been running SR3 for most of a decade. Over that time I developed three different campaigns that all were long-lifed and were actually played concurrently.
The first (and it was the "original" one that we started playing SR) were a group of "traditional" Shadowrunners ; mercs from different backgrounds that hired out their services to Mr. Johnsons. It was set in Seattle. The core group of runners in this were an adept, a rigger, a mage, a weapon specialist, an infiltrator and a PI face.
Within a year, a second game was started, to mostly be a bunch of action and to allow for when the majority of hte core couldn't make it. It was a troll go-gang, also set in Seattle. What started as a "backup game" quickly developed into a regular and very popular mainstay, with the players being disappointed if I announced I was runnign the next week and it wasn't "Da Trolls."
After a couple years I bought the Denver boxed set and I was really taken with the setting and it's different flavor. I started a smaller campaign that also brought in a couple new players that mixed with a couple of old regulars. This group ended up being heavy on the magic, with a gator shaman, an athletic dwarf mage, an adept and a mundane Troll tank as it's core.
All of these campaigns were heavily played and developed very heavy long arcs mixed with one off missions.
So, when I decided I needed to learn 4th edition in order to continue playing in the tourney at Gencon in '06, I pulled out my barely cracked 4th Ed book I had purchased at the '05 Gencon and taught myself the new rules. Then it was time to actually use them. But, what to do? I had been running SR3 for nearly 10 years, nearly every weekend. I wanted the players to have fun doing something more than just learning a new system. I thought "Hey, they have always been "criminals" in some way or another; let's try them on the other side of hte law!" So I half-pre-genned several Lonestar detectives and let them fill them out.
The core characters ended up being:
- Hoolihan, a human SWAT sniper/commander veteren that had been transferred out of SWAT disgracefully (He had accidentally gotten a team member and good friend killed on duty) and assigned as a Vice detective while he waited to retire in 18 months. Imagine Dirty Harry crossed with Murtough from Lethal Weapon.
- His partner Buttercup, a human woman forensics detective that had few social skills which led her to being taken out of hte lab and assigned to partner as a detective with the afformentioned jaundiced SWAT guy to get her out of hte hair of the lab. I kinda saw her as Sandra Bullock-y from Miss Congeniality.
- Pinky, a former undercover orc ganger. He blew his cover to bring down a gang from the inside and was reassigned to Vice as a detective. The player went for "Ving Rhames as an orc" as his theme.
- His Partner "Lucky" Mendez, a troll seargent, who, after taking the detective exam a record 11 times, finally made detective with the lowest possible qualifying score. He was also addicted to gambling.
- Bob Ford, an elf adept undercover Internal Affairs detective searching out corruption within the department.
- I added, as an NPC, a troll mage/detective. He frequently partnered up with either Pinky or the IA guy as needed.
They were stationed in a hell hole of a precinct... a real Siberia. I had great fun ripping off every cliche' from every buddy cop movie and
Nash Bridges and
Dirty Harry,
LA Confidential,
6 Blocks etc. They had the typical swearing, shouting captain who could never get their names right, a pair of "rival" detectives that fragged with them constantly, colorful gang members, eccentric criminals and so on.
So, by the time Gencon '06 rolled around, I knew 4th Ed. pretty well. I was ready for it. So, imagine my delight when we played and the scenario was "3rd Law" Yup, the scenario that year was a bunch of cops, FBI, CIA, NSA agents all working together as a joint task force to capture a terrorist. Talk about serendipity!I got to play the adept Federal Marshall Nelson. And my team won the event! After years of playing in it and never having a podium finish, I managed a win!
Well, after that, I brought that Gencon character home to my own game as an NPC. I created a huge murder mystery for the players that played out a lot like a mix of LA Confidential and 6 Blocks. IN the end, the characters uncovered a huge corrupt scheme within Lonestar and a bunch of dirty cops and judges. After busting the case wide open (and killing some cops), there was no way they were returning to their former jobs. Fortunately Marshall Nelson, after his success with the terrorist joint task force, was now heading up his
own team of agents.

He convinced all the former detectives to sign on with the Marshall service and, after free cosmetic surgery, they became a
Mission Impossible type of team, infiltrating, going deep undercover, attending to national security, body guarding VIPs, etc.
So, I know from experience that you can have a GREAT time playing cop type figures and it can be a really long lived campaign. Good luck to anyone that decides to go this route.
Vlad