Get the owner of a process, without using slow WMI calls

ProcessOwner.cs

[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool OpenProcessToken(IntPtr ProcessHandle, uint DesiredAccess, out IntPtr TokenHandle);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool CloseHandle(IntPtr hObject);

internal static string GetProcessUser(Process process, bool includeDomain = false)
{
    var processHandle = IntPtr.Zero;
    try
    {
        OpenProcessToken(process.Handle, 8, out processHandle);
        var wi = new WindowsIdentity(processHandle);
        var user = wi.Name;
        if (!includeDomain) return user.Contains(@"\") ? user.Substring(user.IndexOf(@"\") + 1) : user;
        else return user;
    }
    catch
    {
        return null;
    }
    finally
    {
        if (processHandle != IntPtr.Zero)
        {
            CloseHandle(processHandle);
        }
    }
}