SAN ANTONIO -

A 29-year-old San Antonio man plead guilty to murder charges just as his trial was to begin for the day on Wednesday.

Daniel Reyes was on trial for stabbing James Weidenhold, 67, to death.

Weidenhold, a neighbor, had tried to intervene in a violent argument between Reyes and his wife and had threatened to call police.

The couple’s son witnessed the attack that occurred on Aug. 12, 2012, outside the family’s apartment.

“My client decided this morning -- with no real warning -- (that) he would not go through with putting pressure on his children by having them testify against him,” said Reyes' attorney, Mike Sawyer.

Prosecutors had indicated that Reyes' son, who turned 11 years old Wednesday, was among the witnesses they planned to call.

“He saw his father stab Mr. Weidenhold and he saw all of the arguing beforehand between his mother and father,” said prosecutor Wendy Wilson-Ortiz.

Part of the plea bargain called for Judge Melisa Skinner to make an affirmative finding that Reyes’ used a deadly weapon in the murder.

That means Reyes must serve half of his 50-year sentence before he is eligible for parole.

For a list of recent stories Paul Venema has done, click here.