Stolen gun used in Highlands students' murder-suicide linked to shooter's cousin

Louis Nickerson, Clarissa Riojas signed 'stay away agreement' before shooting

SAN ANTONIO – Investigative files released to the KSAT 12 Defenders confirm the gun used by a Highlands High School student in April to shoot and kill his former girlfriend and then himself had been stolen from a San Antonio-area Little Caesars months earlier.

Louis Nickerson, 19, used the gun April 25 to shoot through the door of a second-floor apartment in the 3900 block of Southeast Military Drive before shooting his ex-girlfriend, 18-year-old Clarissa Riojas, twice in the head, SAPD records confirm.

The handgun, a Glock 42 .380 pistol, was later recovered from the right hand of Nickerson, whose body was found in a wooded area near the apartment.

Nickerson died of a self-inflicted gunshot wound to the head, according to an autopsy performed by the Bexar County medical examiner.

The SAPD detective assigned to the case was able to confirm in early May that the gun used in the fatal shootings was the same one stolen from a Little Caesars off of FM 78 last December, according to SAPD records.

An employee working at the pizza restaurant told a Bexar County Sheriff's Office investigator that a 17-year-old co-worker likely took the gun after she refused to sell it to him.

The teen, who remains a suspect in the stolen firearm case, is described as Nickerson's cousin and a fellow classmate at Highlands.

SAPD records show the teen late last year was confronted by a manager at the pizza restaurant and although he denied taking the gun, he left work after the confrontation and never returned.

KSAT 12 is not naming the teen unless he is charged in connection with the BCSO stolen firearm case.

Theft of a firearm is a state jail felony.

A man living at the teen's home confirmed SAPD records that indicate Nickerson had previously told his cousin he wanted to kill Riojas.

"Every time they got into it, him and that girl, he would say something like that. (Redacted) just blew it off as he really didn't think that this guy was going to do something like this," the man said.

"These families want somebody to pay, even though you were ignorant to the fact that you gave him that gun, I said, 'It's not over,'" the man added, describing conversations he has had with Nickerson's cousin since the murder-suicide.

It remains unanswered how soon before the shooting Nickerson took possession of the gun and how he got to Riojas' apartment the morning of the murder-suicide.

The release of San Antonio Police Department files comes weeks after San Antonio Independent School District officials publicly defended their handling of the teens prior to the April 25 shooting.

An SAISD spokeswoman confirmed Riojas and Nickerson signed a "stay away agreement" April 11, after Riojas' mother came to campus and complained about Nickerson's ongoing harassment of her daughter.

The agreement required the teens to not come into contact with one another while on campus.

SAISD officials have so far refused to release copies of the agreement, citing a portion of the Texas Government Code related to confidential information in a letter sent to the state attorney general's office late last month.

"It was taken very seriously, a number of things were put in place, and we did provide her with a safe environment at school," said district spokeswoman Leslie Price.

Price said that within 90 minutes of the agreement being signed, Highlands staff members were made aware of it.

Riojas' parents have criticized the district for not making SAISD police aware of the agreement, since Riojas had told school officials Nickerson had twice physically assaulted her off campus in the past.

Price said whether or not to include district police is decided on a case-by-case basis and that they were not included in this agreement because both assaults happened off of school grounds and there had been no recent physical abuse of which the district was aware.

Prince said instead, a school social worker recommended to Riojas that she file criminal charges with SAPD.

Price said an assistant principal at Highlands urged Riojas' mother to go to SAPD as well.

It remains unclear if Riojas contacted SAPD prior to the shooting.

Riojas' father told the Defenders last month that an assistant principal called him 45 minutes after the shooting, demanding to know what had happened.

He described the administrator's tone as "insensitive."

"I don't know all of the conversations, the words that were used, the tone that was used. What I do know is that school administration and faculty were very shaken up by what happened, very upset by what happened. If that didn't come across to the family, then that's very sad, because we want them to know how devastated everyone was," Price said.

A Defenders investigation in May revealed that SAPD officers responding to the shooting were originally dispatched to the wrong address.

The error took more than five minutes to correct, according to audio released to the Defenders.

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