Grelvis Estevez Cabrera and Carlos Nathaniel Landesta-Agramonte are charged with conspiracy to commit criminal homicide and tampering with evidence, according to the Lehigh County District Attorney's Office.
Officials have said Martinez-Velez, 25, was shot to death at the basketball court in Fountain Park last Saturday, June 1.
In a release on Thursday, June 6, the DA's Office said two vehicles were seen fleeing the park: a dark-colored Honda and a white car.
Using public surveillance cameras and license plate readers, police were able to identify the Honda's license plate and spot a passenger that matched witness descriptions of the shooter, authorities said.
The second car was identified as a white Infinity registered to Landesta-Agramonte, according to officials.
Police tracked down both vehicles at Landesta-Agramonte's East Court Street home within two hours of the shooting, the DA's Office said.
On Wednesday, June 5, 18-year-old Landesta-Agramonte and 27-year-old Estevez Cabrera were taken into custody at the Allentown police station. Both are being held without bail and have preliminary hearings scheduled for June 11.
Investigators believe there may be more suspects.
"The investigation remains ongoing and we continue to ask the community for information and assistance to help identify and find others who may also be involved in the killing," said the DA's Office on Thursday.
"These arrests are the accumulation of dedicated law enforcement officers and city officials as well as those in the community who have provided critical tips to help solve this homicide."
Loved ones have launched a campaign on GoFundMe to raise money for Martinez-Velez's funeral costs. The 25-year-old was a "great friend, brother, son, husband and father," organizers said.
Click here to view the fundraiser on GoFundMe.com.
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