SAN ANTONIO — A newly released affidavit for an arrest warrant in the murder of a local teacher offers a chilling look inside the investigation.
Thursday night 25-year-old Mathew Wiessing was arrested and charged in connection with the death of Michael Echaniz, on March 10.
Echaniz worked at the Great Hearts Forest Heights charter school campus.
The arrest document says the two men both worked at the school for a time, and that the victim was dating a woman who had previously ended a relationship with Wiessing.
The affidavit details the evidence detectives have been able to gather since the early morning attack at the Eckert Heights apartment complex in the 4800 block of Gus Eckert Road.
Investigators say an eyewitness saw Wiessing hiding near a dumpster before hearing the gunshots that claimed the life of the well-regarded educator.
Other witnesses told police they saw a slim-framed white male wearing a dark hoodie run from the area.
Police say surveillance video shows Wiessing’s car entering the complex a few minutes before the shots were fired, and leaving a few minutes after 911 calls were made to police, and that when they examined data from Weissing’s cell phone, they found evidence that he had been in the area at the time.
The affidavit goes on to say that another surveillance camera at the corner of Gus Eckert and Fredericksburg Road captured video of Wiessing’s car blowing through the red light and nearly crashing into a passing school bus, as he left the area.
Investigators say there is also surveillance video showing Wiessing returning home about 10 minutes after the shooting.
In the hours after the attack, detectives say Wiessing’s mother told them he was away from home during the time of the murder and when he returned, he put his dark hooded jacket in the wash.
The mother also told police her son had been coming and going from the house at odd hours of the day and night in recent weeks and that two guns were missing from the home.
Quoting from the affidavit, the mother “reported that she feared that Wiessing would commit a violent act at the church” where a prayer event was being held for the victim the night of the attack.
Police said they conducted a traffic stop when they found Wiessing driving near the church, and they questioned him, but the affidavit claims at the time they didn’t have enough evidence to arrest him, so he was released.
Investigators say Wiessing’s answers to questions were evasive and when pressed, Wiessing requested an attorney and quit talking.
A person who answered the phone at the church connected to family members did admit that prayers had been offered for the victim, but declined to discuss the alleged threat, wishing our caller a blessed day.
Police say Wiessing was arrested without incident. He remains in the Bexar County Jail under a $250,000 bond.
School officials from Great Hearts Forest Heights previously confirmed to KENS 5 that Echaniz was a teacher at the charter school.
After the arrest, Great Hearts send the following letter to families:
Great Hearts San Antonio Families,
Today, the San Antonio Police Department made an arrest in connection to the tragic death of Michael Echaniz on March 10th. Mr. Echaniz was a Teacher Assistant and beloved colleague at Great Hearts Forest Heights.
The suspect arrested is Matthew Wiessing, a former Great Hearts Texas employee who was a Teacher Assistant at Forest Heights until resigning in August of 2021. Prior to working at Forest Heights, Mr. Wiessing spent one year in the same role at Great Hearts Irving.
The case is in the hands of the legal system, and we will continue to cooperate with law enforcement. All questions regarding the case should be directed to the San Antonio Police Department. As local authorities continue their work, Mr. Echaniz’ family, friends, and students are ever in our thoughts and prayers.
Sincerely,
Brendan Miniter
Superintendent, Great Hearts Texas