LINQ-2

using System;
using System.Collections.Generic;
using System.Linq;

namespace Homework2
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Criminal> criminals = new List<Criminal>
            {
                new Criminal("a","Антиправительственное"),
                new Criminal("b","Антиправительственное"),
                new Criminal("c","Антиправительственное"),
                new Criminal("d","Неантиправительственное"),
                new Criminal("e","Неантиправительственное"),
            };

            var filteredCriminals = criminals.Where(criminal => criminal.Offence != "Антиправительственное");

            foreach (var criminal in criminals)
            {
                criminal.ShowInfo();
            }

            Console.WriteLine("----------------------");

            foreach (var criminal in filteredCriminals)
            {
                criminal.ShowInfo();
            }
        }
    }

    class Criminal
    {
        public string Initials { get; private set; }
        public string Offence { get; private set; }

        public Criminal(string initials, string offence)
        {
            Initials = initials;
            Offence = offence;
        }

        public void ShowInfo()
        {
            Console.WriteLine($"{Initials}|{Offence}");
        }
    }
}