SAN ANTONIO, Texas (WTVO) — The cousin of the Uvalde school shooter was arrested Monday after police say he attempted to purchase an AR-15 rifle with the intention of committing a mass shooting.

Nathan Cruz, 17, the cousin of Salvador Ramos — who shot and killed 19 students and two teachers at Robb Elementary School in Uvlade, Texas last May — faces charges of making a terroristic threat to a public place and to a family member, according to KSAT.

San Antonio Police were contacted by Cruz’s mother on Monday after her daughter told her that Cruz said he planned “to do the same thing” as his cousin, according to an affidavit obtained by CNN.

According to Cruz’s sister, the 17-year-old had “threatened to shoot her in the head and stated he would ‘shoot the school,” during a car ride.

The mother reportedly told detectives she had overheard a phone call Monday morning in which Cruz “attempted to acquire an AR-15 through an illegal private sale” and that she was “especially concerned” because the family lives across the street from an elementary school.

A warrant for Cruz’s arrest was issued following police investigation. He was arrested “without incident” and booked into the Bexar County Jail.

Cruz has reportedly denied the allegations.