iOS Core Data Memory Leak

/*
     Fetch existing events.
     Create a fetch request; find the Event entity and assign it to the request; add a sort descriptor; then execute the fetch.
     */
    marblebeingdragged=YES;
	NSFetchRequest *request = [[NSFetchRequest alloc] init];
	NSEntityDescription *entity = [NSEntityDescription entityForName:@"Child" inManagedObjectContext:_managedObjectContext];
	[request setEntity:entity];
	
	// Order the events by creation date, most recent first.
	NSSortDescriptor *nameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:NO];
    NSSortDescriptor *prizeDescriptor = [[NSSortDescriptor alloc] initWithKey:@"prize" ascending:NO];
    NSSortDescriptor *neededDescriptor = [[NSSortDescriptor alloc] initWithKey:@"marblesneeded" ascending:NO];
    NSSortDescriptor *colorDescriptor = [[NSSortDescriptor alloc] initWithKey:@"color" ascending:NO];
    NSSortDescriptor *reachedDiscriptor = [[NSSortDescriptor alloc] initWithKey:@"prizereached" ascending:NO];
    
	NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:nameDescriptor,prizeDescriptor,neededDescriptor,colorDescriptor, nil];
	[request setSortDescriptors:sortDescriptors];
	[nameDescriptor release];
    [colorDescriptor release];
    [prizeDescriptor release];
    [neededDescriptor release];
    [reachedDiscriptor release];
	[sortDescriptors release];
	
	// Execute the fetch -- create a copy of the result.
	NSError *error = nil;
    records = [[self.managedObjectContext executeFetchRequest:request error:&error] retain];
    
    [request release];

 records = [[self.managedObjectContext executeFetchRequest:request error:&error] retain];