If you haven't already, check out this collection of information:
http://www.nraila.org/
and this one:
http://www.cato.org/pubs/pas/pa109.html
It has stuff about concealed carry, as well as most other topics. You will probably want to find Lott's "More Guns Less Crime" to back up the effectiveness of concealed carry. If you can convince the class the second means what it says, obviously "bear" is analagous to right-to-carry.
Since he's a policeman, he probably has some tragic, emotional stories he will want to share- ie, this little kid accidentally shot his brother, a wife beater shot his wife ect. You need to prepare to answer emotional arguments with facts. Since he's a "authority figure" the audience will probably take him at his word when he says something like "This will make police work even more difficult!" or "Citizen's aren't trained or capable to use these weapons properly." It might be helpful to point out that police gun down more innocent people accidentally, than do armed citizens. The second URL at the top has number of those killed by police & civilians.
If you are lucky, he will say something like "People with Concealed Carry licenses might shoot someone in a fit of "Road Rage" after a car accident!" If so, jump on him with the fact that, in the DECADES such licences have been issued NO holder has EVER murdered someone after a car accident. There was one killing- but the court ruled it self defense.
Remind your audience that license holders have to go through a background check, and, depending on the area, may have to show gun proficiency. Very few of them have been revoked for misdeeds- the NRAILA site above has the % of Florida liscenseholders who have had theirs revoked.
Since he's a cop, it might help to ask your audience hypothetical questions like: "My neighbor is threatening to kill me. Do the police have a duty to protect me?" or "If I dialed 911, and the police did not arrive for 30 minutes, and a family member was murdered, are the police liable?" The answer is, of course, NO. There are various court rulings stating the police have a duty to protect society at large, and enforce the law, but NO DUTY WHATSOEVER to protect individual citizens, even if they recieve death threats. One of the court's statements went something like this: "There is no constitional right to not be murdered." If you use that, you'll need to get the actual ruling. I'll look and see if I can find it.
It could be helpful to question your policeman about certain things: "What percentage of home burglars do police stop, by being at the right place and the right time?" "How often to police catch muggers in the act?" "What percentage of carjackings are caught in the act by police?" "When a store is robbed, how often do the police catch the robber in the act?" Of course, any time you ask an opponet such questions, you need to prepare to respond effectively if he does not answer like you expect.
It might be helpful to sound concilatory, maybe make some kind comments about police, say the liscenseholders are a supplement and a help to the police, ect.
Prepare for every eventuality, use stats if you can back them up well and provide references. Good luck!
[This message has been edited by BTR (edited October 06, 1999).]