Serious doubts concerning the evidence of Dutch girls' case

On 18 June, locals found a blue boot with a white sole on the banks of the Culubre river, located in the Bocas del Toro province. The boot was dry and severely damaged.

Seen through photographs taken on site, it seems to fit the right foot. This was the second shoe found by locals on the banks of the river. Two days before, on 16 June, another boot was found, a brown one with human remains inside.

The brown shoe was handed over to the Prosecution of David, Chiriquí province, where the investigation of the disappearance from both Dutch girls is taking place.

The Prosecutors were interested in finding out if the human remains belonged to one of the girls.

Lisanne Froon and Kris Kremers were last seen on 1 April, when they entered the Pianista trail near Boquete, Chiriquí.

Ever since then, all the information about the missing girls comes from their belongings and human remains that have been found spontaneously on the banks of the Culubre river, 12 hours on foot from the place where the girls were last seen.

The first shoe, the brown one, contained human remains from Lisanne. The boot was analyzed by the Biomolecular Lab from the Institute of Legal Medicine and Forensic Sciences (IMELCF).

Reports provided by the Lab state that the remains found inside the shoe were a metacarpus (the intermediate part of the hand skeleton).

According to medical examiners consulted by this journal, the remains should have been subjected to a fluid detection analysis. The Prosecution seems to have skipped these steps. 
Betzaida Pittí, prosecutor in charge of this case, also obviated to run DNA tests to the shoe. Nevertheless, investigators related the boot to the girls, because it was a shoe of the Dutch brand 'Wildebeast'.

The blue boot should have belonged to Kris Kremers, so the Prosecution. It was found by locals Ángel Palacio and Feliciano González, according to news reports.

Even though there's no scientific proof that the shoe belonged to Kremers, it was added to the evidence of the case.

For the Prosecutor, the girls' death was an accident. Pittí has repeated on several occasions that the Pianista trail is not free from wild animals and snakes.

However, Enrique Arrocha, lawyer of the Kremers family, sustains that the girls were murdered.

This is why serious doubts arise regarding the blue shoe. The main doubt comes from the fact that there's no DNA test that proofs the shoe belonged to Kris.

La Estrella de Panamá confirmed that the IMELCF, only lab in the country that performs the required analysis for the evidence, hasn't received the shoe.

It is also unclear if the Prosecution showed the blue boot to the Kremers family, so they could identify it as one of Kris' belongings.

In the pictures taken previous to their disappearance, Kris wears brown boots, both at the airport and on the day she entered the Pianista trail.

Can the Prosecution proof that this shoe belonged to Kris, despite the color? How can the Prosecution explain the 'change' of color, from brown to blue? What's the shoe size and what's the brand? Was the shoe handed over to the Kremers family for a recognition? What was their answer? And if not, why?

These questions could have an answer if a proper investigation, which beholds DNA tests, took place.

Spanish version here.