<?php

namespace AppHttpControllers;

use IlluminateHttpRequest;
use AppDenuncia;
use IlluminateSupportFacadesDB;

class AlunoController extends Controller
{
    public function alunoInsert(Request $request)
    {
        $denuncia = Denuncia::create([
            'descricao' => $request->form,
            'qual_descricao' => $request->oque,
            'id_bloco' => $request->bloco,
            'id_denuncia_oque' => $request->local,
            'id_usuario' => 63,
            'imagem' => 'padrao.jpeg',
        ]);

        return response()->json($request);
    }
}

<?php

namespace App;

use IlluminateDatabaseEloquentModel;

class Denuncia extends Model
{
    protected $table = 'denuncia';

    CONST CREATED_AT = 'data';
    CONST UPDATED_AT = 'data_atualizacao';

    protected $guarded = [];
}

$denuncia = Denuncia::create([
    ...
    'imagem' => $path,
]);