Texas Man Allegedly Killed His Ex-Girlfriend’s New Boyfriend, An Elementary School Teacher

A Texas man has been arrested for allegedly shooting his ex-girlfriend’s new boyfriend to death earlier this month.

The San Antonio Police Department announced on Thursday that they have arrested Mathew Wiessing, 25, for the March 10 murder of Michael Echaniz, 23. The young teacher had been shot to death as he was getting into his car at his apartment complex that morning, Lt. Michelle Ramos of the San Antonio Police Department told reporters on Thursday. He was en route to his job as a fifth and sixth grade teacher at Great Hearts Forest Heights, an elementary school in San Antonio.

According to an arrest report obtained by San Antonio NBC affiliate WOAI, Echaniz had a gunshot wound to his right hand, which they classified as a defensive wound, a gunshot wound to his upper back and two gunshot wounds to his head. Shell casings were found around the scene — including one on his chest.

Jealousy was cited as the motive.

“Mr. Wiessing was involved in a relationship with a woman," Lt. Ramos said. "That relationship, for some reason, ended several months ago. And the victim, Mr. Echaniz, was currently dating that ex-girlfriend.”

For a few weeks, police sought out the shooter; initially, there was no description of the shooter except for the fact that he was wearing a dark hoodie and glasses at the time of the killing.

“Detectives developed Wiessing as a suspect and through evidence and information obtained, he was charged with the murder,” police stated in their release.

Lt. Ramos said it was a relative of Wiessing that helped lead to his capture..

“That family member had information that [Wiessing] was gone during the time of the shooting, and when he returned was doing things that he would not normally do,” she said. “That family member also stated that there was a nine-millimeter handgun missing from the home, and we know that the gun used for the murder was a nine-millimeter.”

The family member also noted that Wiessing had taken his November 2021 break-up — with the girl Echaniz was dating at the time of his death — particularly hard.

From there, police located the suspect’s car and conducted a traffic stop. He agreed to an interview where he was “very evasive and didn’t answer too many questions,” Lt. Ramos said.

“So we did not have enough probable cause to arrest and at that time he was released," she stated.

From there though, detectives gathered other evidence — including video footage captured in the area.

“During the course of that investigation, they were able to locate evidence, specifically surveillance video evidence, which showed Mr. Wiessing going to the crime scene just as it happened and then fleeing the crime scene right after the shooting,” Ramos told reporters.

It’s not clear if Wiessing has an attorney. He remains in custody on a $250,000 bond, officials with the Bexar County Jail confirmed to Oxygen.com.

Members of his Echaniz's high school graduating class have now established the “The Michael Echaniz Teacher of the Year Award” in his honor.

“Michael Echaniz was a faithful Catholic, a dedicated teacher, and a wonderful friend to many,” his former classmates wrote. “To those that were close to him throughout his days at Chelsea Academy, he was always a truly selfless friend and brought a bright spark of humor to many of his classmates.”