PHP - Caracteres especiales Ver tildes y ñ conexion php a mysql

<?php

    $con = mysqli_connect("localhost", "root", "", "sane");

    $username = $_GET["username"];

    $password = $_GET["password"];

    if (!mysqli_set_charset($con, "utf8")) {

        printf("error");

    }else{

        //Para que le ponga el utf8 para que me aparescan las tildes y ñ

    mysqli_character_set_name($con);

    $statement = mysqli_prepare($con, "SELECT * FROM users WHERE usuario = ? AND pass = ?");

    mysqli_stmt_bind_param($statement, "ss", $username, $password);

    mysqli_stmt_execute($statement);

    mysqli_stmt_store_result($statement);

    mysqli_stmt_bind_result($statement, $userID, $nombre, $username, $password);

    $response = array();

    $response["success"] = false;

    while(mysqli_stmt_fetch($statement)){

        $response["success"] = true;

        $response["nombre"] = $nombre;

        $response["usuario"] = $username;

        $response["pass"] = $password;

    }

    echo json_encode($response);

    }

?>

<meta charset="utf-8">