A vigil for Nabra Hassanen takes place at Lake Anne Plaza in June near Reston, Va. (Katherine Frey/The Washington Post)

A man set for a capital murder trial in the high-profile killing of a Muslim teen in Virginia is “likely intellectually disabled” and should be evaluated to determine whether he has the mental capacity to face the death penalty, according to a neuropsychologist.

Attorneys for Darwin Martinez Torres cite the findings in recent motions seeking the appointment of the expert to further evaluate their client’s intellectual abilities and a neurotoxicologist to probe his brain development.

Torres is facing counts of murder, rape and other charges in the brutal slaying of Nabra Hassanen, 17, of Reston, whose death in June generated national attention and sparked vigils from coast to coast. He is slated to stand trial in January in Fairfax County.

Defense attorneys declined to comment, but they wrote in their motions that a neuropsychologist who evaluated Torres, 23, of Sterling, found he had significant cognitive limitations, poor memory and severely impaired judgment. He is also functionally illiterate and does not have a high school diploma.

Nabra Hassanen (Family photo/AP)

Their investigations in Torres’s home country of El Salvador determined he was exposed to mercury, cyanide, arsenic and potentially other neurotoxins in utero and in his early years, possibly slowing his brain development, according to the motions. They do not disclose the exact source of the pollutants.

“His environment was a virtual toxic dump site due to industry and particular toxic waste being dumped into the ground and directly into surface and groundwater,” the attorneys wrote.

The Supreme Court has ruled that executing a person with serious intellectual disabilities violates the Eighth Amendment ban on cruel and unusual punishment. Courts typically appoint psychologists to determine if defendants meet such criteria. A Fairfax County judge is scheduled to hear Torres’s motions May 24.

In a separate motion filed in April, the attorneys asked for monthly motion hearings in the case to be slowed because Torres was having trouble following the legal arguments because of his disabilities. A judge allowed Torres’s attorneys to ask for breaks between arguments to get him up to speed.

Fairfax County Commonwealth’s Attorney Raymond F. Morrogh declined to comment on the defense motions. Responses filed by prosecutors were not available in court Friday.

Fairfax County police said Torres abducted Nabra, driving up to her and about 15 other teens walking back to the All Dulles Area Muslim Society mosque in Sterling after a meal around 3:40 a.m. on June 18. The teens had been celebrating the customary pre-dawn meal during the holy month of Ramadan.

Torres got into an altercation with a teen on a bike and then chased the teens over a grassy area in his car, sending them fleeing, police said. Torres chased them to a parking lot and got out of his car with a baseball bat and ran after them again.

One of the teens looked back to see Torres standing over Nabra, who was lying on the ground, according to a search warrant. Police said Torres hit Nabra with the bat at some point and then loaded her into his Pontiac sedan.

He drove Nabra a short distance, raped her, killed her and dumped her body in a pond near his Sterling apartment complex, police said. Torres returned to the scene of the abduction and was apprehended by police.

He later led police to her body and admitted his role in her killing, according to the search warrant. Nabra’s friends, family and members of the local Muslim community have questioned whether hate may have motivated the attack, but police said they have not found any evidence Nabra was targeted because of her faith.

The filings also fill in the scant details that are publicly known about Torres. Defense filings show Torres was homeless for a time before he turned 18 and lived at the Loudoun Youth Shelter while he was awaiting the resolution of unspecified charges against him in juvenile court. Those charges eventually were dropped by Loudoun prosecutors, but the court filings do not explain why.

A week before the killing, a woman reported that Torres had punched, choked and sexually assaulted her. Loudoun County Child Protective Services reported the incident to police, but the woman told authorities she did not want to pursue charges.