An investigation carried out by judge Carlos A. Valcárcel later managed to collect at least twenty three depositions that incriminated O'Donnell in the Putumayo genocide.

[8] When Andrés arrived to Entre Rios in 1903 there was an old great Native chief named Chingamuni, who still retained influence over the local Huitoto population.

On the way back with O'Donnell from La Chorrera after a fabrico, Chingamuni was killed during a quarrel by a Colombian named Calderon who also worked for Arana.

The Colombians "'treated' the Natives 'very badly,'" according to O'Donnell they were "much worse than he and the Peruvians... it was simply 'conquering' Indians and holding them as slaves – killing them and their women and living entirely on them."

[9] A judicial investigation that occurred after O'Donnell's employment with the Company implicated him with the September 24 1903 massacre of Ocaina natives at La Chorrera, ordered by Benjamin Larrañaga.

[3] According to the Entre Rios pay sheet, Andrés made 3 Peruvian soles per arobba, and 7% commission on the rubber his station collected.

Roger Casement estimated the road from the port to Entre Rios to be between 12 and 14 miles in total, which was developed and maintained with an enormous effort from the Natives.

During the last fabrico of 1910 and Casement's investigation, the manager of Matanzas, Armando Normand, and his enslaved Native workers had to pass through Entre Rios to get to Puerto Peruano.

The volunteered self explanation that later came from Normand was that he was avoiding O'Donnell's crop fields since the Matanza's Natives constantly stole food from there.

[20] Andrés O'Donnell was still working for the Peruvian Amazon Company by the time Roger Casement left the Putumayo in November 1910.

[21] During O'Donnell's management of the Entre Rios station, multiple Huitoto and Bora tribes were enslaved and induced to extract rubber for the Company.

[25] Depositions that were collected by Hardenburg relating to O'Donnell include Daniel Collantes; Marcial Gorries; and Juan Rosas.

[26][27] Daniel Collantes gave a long testimony of crimes in the Putumayo, and mentioned O'Donnell in passing regarding an incident that happened with Elias Martinengui.

In the conclusion of Collantes statement, Daniel gives a list of names he refers to as diabolical criminals including Andrés O'Donnell and other managers who worked for Arana.

The letter stated the "principal criminals" are the Chiefs of Sections, and lists of names including Armando Normand; José Inocente Fonseca, Augusto Jiménez Seminario, Andrés O'Donnell and six others.

[29] [30] In Juan Rosas deposition, he states that O'Donnell induces the Natives to deliver a quota of rubber to him, and when they do not "he submits them to most cruel punishments, mutilating them and then ending by murdering them."

[7] An investigatory commission was sent by the Peruvian Amazon Company in 1910, which the British Foreign office attached Roger Casement to learn about the treatment of Barbadians in the Putumayo.

The Barbadians who made depositions to Roger Casement and mentioned their time working for Andrés O'Donnell include Frederick Bishop, James Chase, Allan Davis, Joseph Minggs, Augustus Walcott, and Sidney Morris.

Bishop heard O'Donnell send out his muchachos de Confinzas to kill natives in the forest "if rubber was not forthcoming," however he has no knowledge about those individual actions.

According to Judge Valcárcel's investigatory report, while laying in his hammock, O'Donnell shot around 40 natives, men and women who were placed in a row in front of him.

[40] Nicolas and three other Natives helped the judge Valcárcel discover the burial site of Sofia, Papaire and Salvador, who were either murdered by O'Donnell or ordered to be executed by him.

[39] The Company employee Froilán Patiño testified to Valcárcel that he witnessed O'Donnell commit numerous crimes against the Natives around the Entre Rios and Sabana stations.

[44] Quimedire Witoto reported that he saw O'Donnell personally kill four Natives from the Timenses Nation who were not bringing in rubber, and he flogged many others.

In his letter to Spicer, Casement wrote "I don't think he [O'Donnell] killed Indians for pleasure or sport – but only to terrorize for rubber – a thing he was appointed to do by his superiors.

"[45] Casement also wrote the following regarding O'Donnell "he had a very well kept and well planted station and his Indians seemed happier than any others I met..." however, he continues "it was just the same infamous regime of extortion and terrorism there as elsewhere."

[45] When Roger Casement arrived at Bridgetown in Barbados on December 29, 1911, he found out that O'Donnell was still living in the island as a free man.

Sir Hildred Carlile inquired into the reasoning for that oversight, and expressed to the Peruvian government "his hopes" that they would take steps to extradite O'Donnell from whatever country he sought asylum in.

Marcial was returning from Barbados with a Huitoto woman named Julia, who was reported to be an Indigenous mistress that once belonged to Andres O'Donnell.

[50] An album published by the Peruvian Amazon Company in 1912 contains a photograph from the Entre Rios section titled "The Indian Huitota Julia sewing by machine.

One particular example pointed out is from Robin Furneaux's The Amazon; The Story of a Great River which claimed Casement had a sexual relationship with the Barbadians Stanley Sealey, Westerman Leavine, and the Company manager O'Donnell.