On May 19, 2016, police arrested Diego Uribe, a relative of the family, and his girlfriend, Jafeth Ramos, in connection to the murders, saying that the massacre was a robbery gone wrong.
Rosaura Martinez also rushed upstairs and was allegedly pushed downstairs by Uribe, who then grabbed several knives from the kitchen and stabbed her several times.
Uribe then allegedly forced the young boys to retrieve cash, an Xbox and other valuables from various rooms in the house.
"[9] Uribe then waited for the grandfather, Noe Martinez Sr. to arrive back to house from the store, whereupon he beat and stabbed him to death.
[14] The family dog, Pelusa (Spanish for "fuzzy"), was found alive inside the house covered in blood.
[17] On May 19, 2016, Chicago police announced that they had arrested 22-year-old Diego Uribe and his 19-year-old girlfriend, Jafeth Ramos, in connection with the murders.
[8][9] Uribe and Ramos were in a committed relationship and were living in the Little Village neighborhood of Chicago with their young child at the time of the murders.
[18] Uribe was a frequent visitor to the Martinez household and was apparently a close friend of the two boys, with a neighbor stating, "[he] played with those kids all the time.
Loudes Oliva, who raised Ramos, also stated that Uribe was very controlling of her and did not allow her to take showers, put on makeup or leave their home without his permission.