[Cypress]

Here you go.

pawn Код:

forward Timer(playerid);

public OnPlayerDeath(playerid, killerid, reason)
{
    if(GetPlayerTeam(killerid) == TEAM_GANG)
    {
        SendClientMessage(killerid, -1, "You have killed someone you may get caught by the police");
        SetTimerEx("Timer",30000,0,"d",killerid);
    }
    return 1;
}

public Timer(playerid)
{
    //Do what you want to happen here   
}